Allow the docs site to build doxygen in the mbed-os/platform directory

Author: sg-

doxygen_options.json

@@ -8,5 +8,5 @@
     "PREDEFINED": "DOXYGEN_ONLY \"MBED_DEPRECATED_SINCE(f, g)=\"",
     "EXPAND_AS_DEFINED": "", 
     "SKIP_FUNCTION_MACROS": "NO",
-    "EXCLUDE_PATTERNS": "*/targets/* */features/FEATURE_*/* */features/mbedtls/* */features/nanostack/* */features/storage/* */features/unsupported/* */features/frameworks/* */features/filesystem/fat/* */BUILD/* */rtos/* */events/* */platform/* */cmsis/* */hal/* */features/*"
+    "EXCLUDE_PATTERNS": "*/targets/* */features/FEATURE_*/* */features/mbedtls/* */features/nanostack/* */features/storage/* */features/unsupported/* */features/frameworks/* */features/filesystem/fat/* */BUILD/* */rtos/* */events/* */cmsis/* */hal/* */features/*"
 }