[Mellanox] Support SKU Mellanox-SN5600-V256 (sonic-net#18926)

- Why I did it
Support Mellanox-SN5600-V256

- How I did it
Add relevant files to support the new SKU

- How to verify it
Regression test

device/mellanox/x86_64-nvidia_sn5600-r0/Mellanox-SN5600-V256/buffers.json.j2

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/ACS-MSN2700/buffers.json.j2

device/mellanox/x86_64-nvidia_sn5600-r0/Mellanox-SN5600-V256/buffers_defaults_objects.j2

@@ -0,0 +1 @@
+../../x86_64-mlnx_msn2700-r0/Mellanox-SN2700-D48C8/buffers_defaults_objects.j2

device/mellanox/x86_64-nvidia_sn5600-r0/Mellanox-SN5600-V256/buffers_defaults_t0.j2

@@ -0,0 +1,47 @@
+{#
+    Copyright (c) 2024 NVIDIA CORPORATION & AFFILIATES.
+    Apache-2.0
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+#}
+{% set default_cable = '300m' %}
+{% set ingress_lossless_pool_size =  '73684992' %}
+{% set ingress_lossless_pool_xoff =  '60293120' %}
+{% set egress_lossless_pool_size =  '158229504' %}
+{% set egress_lossy_pool_size =  '73684992' %}
+
+{% import 'buffers_defaults_objects.j2' as defs with context %}
+
+{%- macro generate_buffer_pool_and_profiles_with_inactive_ports(port_names_inactive) %}
+{{ defs.generate_buffer_pool_and_profiles_with_inactive_ports(port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_profile_lists_with_inactive_ports(port_names_active, port_names_inactive) %}
+{{ defs.generate_profile_lists(port_names_active, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_queue_buffers_with_extra_lossless_queues_with_inactive_ports(port_names_active, port_names_extra_queues, port_names_inactive) %}
+{{ defs.generate_queue_buffers_with_extra_lossless_queues(port_names_active, port_names_extra_queues, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_queue_buffers_with_inactive_ports(port_names_active, port_names_inactive) %}
+{{ defs.generate_queue_buffers(port_names_active, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_pg_profiles_with_extra_lossless_pgs_with_inactive_ports(port_names_active, port_names_extra_pgs, port_names_inactive) %}
+{{ defs.generate_pg_profiles_with_extra_lossless_pgs(port_names_active, port_names_extra_pgs, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_pg_profiles_with_inactive_ports(port_names_active, port_names_inactive) %}
+{{ defs.generate_pg_profiles(port_names_active, port_names_inactive) }}
+{%- endmacro %}

device/mellanox/x86_64-nvidia_sn5600-r0/Mellanox-SN5600-V256/buffers_defaults_t1.j2

@@ -0,0 +1,47 @@
+{#
+    Copyright (c) 2024 NVIDIA CORPORATION & AFFILIATES.
+    Apache-2.0
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+#}
+{% set default_cable = '300m' %}
+{% set ingress_lossless_pool_size =  '73684992' %}
+{% set ingress_lossless_pool_xoff =  '60293120' %}
+{% set egress_lossless_pool_size =  '158229504' %}
+{% set egress_lossy_pool_size =  '73684992' %}
+
+{% import 'buffers_defaults_objects.j2' as defs with context %}
+
+{%- macro generate_buffer_pool_and_profiles_with_inactive_ports(port_names_inactive) %}
+{{ defs.generate_buffer_pool_and_profiles_with_inactive_ports(port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_profile_lists_with_inactive_ports(port_names_active, port_names_inactive) %}
+{{ defs.generate_profile_lists(port_names_active, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_queue_buffers_with_extra_lossless_queues_with_inactive_ports(port_names_active, port_names_extra_queues, port_names_inactive) %}
+{{ defs.generate_queue_buffers_with_extra_lossless_queues(port_names_active, port_names_extra_queues, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_queue_buffers_with_inactive_ports(port_names_active, port_names_inactive) %}
+{{ defs.generate_queue_buffers(port_names_active, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_pg_profiles_with_extra_lossless_pgs_with_inactive_ports(port_names_active, port_names_extra_pgs, port_names_inactive) %}
+{{ defs.generate_pg_profiles_with_extra_lossless_pgs(port_names_active, port_names_extra_pgs, port_names_inactive) }}
+{%- endmacro %}
+
+{%- macro generate_pg_profiles_with_inactive_ports(port_names_active, port_names_inactive) %}
+{{ defs.generate_pg_profiles(port_names_active, port_names_inactive) }}
+{%- endmacro %}

device/mellanox/x86_64-nvidia_sn5600-r0/Mellanox-SN5600-V256/buffers_dynamic.json.j2

@@ -0,0 +1,16 @@
+{#
+    Copyright (c) 2024 NVIDIA CORPORATION & AFFILIATES.
+    Apache-2.0
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+#}
+{%- set default_topo = 't0' %}
+{%- set dynamic_mode = 'true' %}
+{%- include 'buffers_config.j2' %}

device/mellanox/x86_64-nvidia_sn5600-r0/Mellanox-SN5600-V256/create_only_config_db_buffers.json

@@ -0,0 +1,7 @@
+{
+    "DEVICE_METADATA": {
+        "localhost": {
+            "create_only_config_db_buffers": "true"
+        }
+    }
+}