docs: Clear _Static_assert related warnings

Unclear why defining _Static_assert(x, y) in PREDEFINED list
doesn't match anything, but defining _Static_assert() does match.

docs/Doxyfile

@@ -302,7 +302,7 @@ EXPAND_ONLY_PREDEF     = YES
 PREDEFINED             = \
     $(ENV_DOXYGEN_DEFINES) \
     __attribute__(x)= \
-	_Static_assert(x) = \
+	_Static_assert()= \
     IDF_DEPRECATED(X)= \
     IRAM_ATTR= \
     configSUPPORT_DYNAMIC_ALLOCATION=1 \

docs/sphinx-known-warnings.txt

@@ -76,63 +76,6 @@ If type alias or template alias:
     void() esp_spp_cb_t(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
     ----^
 
-mcpwm.inc:line: WARNING: Error when parsing function declaration.
-If the function has no return type:
-  Error in declarator or parameters and qualifiers
-  Invalid definition: Expected identifier in nested name. [error at 31]
-    _Static_assert(MCPWM_UNIT_MAX, "MCPWM unit number not equal to chip capabilities")
-    -------------------------------^
-If the function has a return type:
-  Error in declarator
-  If pointer to member declarator:
-    Invalid definition: Expected identifier in nested name. [error at 14]
-      _Static_assert(MCPWM_UNIT_MAX, "MCPWM unit number not equal to chip capabilities")
-      --------------^
-  If declId, parameters, and qualifiers:
-    Invalid definition: Expected identifier in nested name. [error at 14]
-      _Static_assert(MCPWM_UNIT_MAX, "MCPWM unit number not equal to chip capabilities")
-      --------------^
-  If parenthesis in noptr-declarator:
-    Error in declarator or parameters and qualifiers
-    If pointer to member declarator:
-      Invalid definition: Expected '::' in pointer to member (function). [error at 29]
-        _Static_assert(MCPWM_UNIT_MAX, "MCPWM unit number not equal to chip capabilities")
-        -----------------------------^
-    If declarator-id:
-      Invalid definition: Expecting "(" in parameters_and_qualifiers. [error at 29]
-        _Static_assert(MCPWM_UNIT_MAX, "MCPWM unit number not equal to chip capabilities")
-        -----------------------------^
-mcpwm.inc:line: WARNING: Error when parsing function declaration.
-If the function has no return type:
-  Error in declarator or parameters and qualifiers
-  Invalid definition: Expected identifier in nested name, got keyword: sizeof [error at 21]
-    _Static_assert(sizeof( ulp_insn_t ), "ULP coprocessor instruction size should be 4 bytes")
-    ---------------------^
-If the function has a return type:
-  Error in declarator
-  If pointer to member declarator:
-    Invalid definition: Expected identifier in nested name. [error at 14]
-      _Static_assert(sizeof( ulp_insn_t ), "ULP coprocessor instruction size should be 4 bytes")
-      --------------^
-  If declId, parameters, and qualifiers:
-    Invalid definition: Expected identifier in nested name. [error at 14]
-      _Static_assert(sizeof( ulp_insn_t ), "ULP coprocessor instruction size should be 4 bytes")
-      --------------^
-  If parenthesis in noptr-declarator:
-    Error in declarator or parameters and qualifiers
-    If pointer to member declarator:
-      Invalid definition: Expected identifier in nested name, got keyword: sizeof [error at 21]
-        _Static_assert(sizeof( ulp_insn_t ), "ULP coprocessor instruction size should be 4 bytes")
-        ---------------------^
-    If declarator-id:
-      Invalid definition: Expected identifier in nested name, got keyword: sizeof [error at 21]
-        _Static_assert(sizeof( ulp_insn_t ), "ULP coprocessor instruction size should be 4 bytes")
-        ---------------------^
-mcpwm.inc:line: WARNING: doxygenfunction: Unable to resolve multiple matches for function "_Static_assert" with arguments () in doxygen xml output for project "esp32-idf" from directory: xml_in/.
-Potential matches:
-    - _Static_assert(MCPWM_UNIT_MAX, "MCPWM unit number not equal to chip capabilities")
-    - _Static_assert(sizeof( ulp_insn_t ), "ULP coprocessor instruction size should be 4 bytes")
-
 #
 # Issue present only when building on msys2 / mingw32 END <<<
 #