minimal-printf: Disable floating point support by default

Mbed OS should not require floating point in its base configuration.
This provides further code size savings out of the box.

TESTS/mbed_platform/minimal-printf/compliance/test_app.json

@@ -0,0 +1,7 @@
+{
+    "target_overrides": {
+        "*": {
+            "platform.minimal-printf-enable-floating-point": true
+        }
+    }
+}

platform/mbed_lib.json

@@ -140,7 +140,7 @@
         },
         "minimal-printf-enable-floating-point": {
             "help": "Enable floating point printing when using mprintf profile",
-            "value": true
+            "value": false
         },
         "minimal-printf-set-floating-point-max-decimals": {
             "help": "Maximum number of decimals to be printed",

platform/source/minimal-printf/README.md

@@ -41,7 +41,7 @@ Minimal printf is configured by the following parameters defined in `platform/mb
         },
         "minimal-printf-enable-floating-point": {
             "help": "Enable floating point printing when using minimal-printf profile",
-            "value": true
+            "value": false
         },
         "minimal-printf-set-floating-point-max-decimals": {
             "help": "Maximum number of decimals to be printed",
@@ -51,7 +51,7 @@ Minimal printf is configured by the following parameters defined in `platform/mb
 }
 ```
 
-By default, 64 bit integers, floating point  and FILE stream printing are enabled.
+By default, 64 bit integers and FILE stream printing are enabled.
 
 If your target does not require some options then you can override the default configuration in your application `mbed_app.json` and achieve further memory optimisation (see next section for size comparison numbers).