Include doxygen from test directories

Turn on doxygen for tests. This allows testing functions to be
referenced, which will be used for various parts of the HAL
specification.

Author: c1728p9

doxyfile_options

@@ -837,7 +837,6 @@ EXCLUDE_SYMLINKS       = YES
 # exclude all test directories for example use the pattern */test/*
 
 EXCLUDE_PATTERNS       = */tools/* \
-                         */TESTS/* \
                          */targets/* \
                          */BUILD/* \
                          */rtos/TARGET_CORTEX/rtx* \

doxygen_options.json

@@ -8,5 +8,5 @@
     "PREDEFINED": "DOXYGEN_ONLY DEVICE_ANALOGIN DEVICE_ANALOGOUT DEVICE_CAN DEVICE_ETHERNET DEVICE_EMAC DEVICE_FLASH  DEVICE_I2C DEVICE_I2CSLAVE DEVICE_I2C_ASYNCH DEVICE_INTERRUPTIN DEVICE_LOWPOWERTIMER DEVICE_PORTIN DEVICE_PORTINOUT DEVICE_PORTOUT DEVICE_PWMOUT DEVICE_RTC DEVICE_TRNG DEVICE_SERIAL DEVICE_SERIAL_ASYNCH DEVICE_SERIAL_FC DEVICE_SLEEP DEVICE_SPI DEVICE_SPI_ASYNCH DEVICE_SPISLAVE DEVICE_STORAGE \"MBED_DEPRECATED_SINCE(f, g)=\" \"MBED_ENABLE_IF_CALLBACK_COMPATIBLE(F, M)=\"",
     "EXPAND_AS_DEFINED": "", 
     "SKIP_FUNCTION_MACROS": "NO",
-    "EXCLUDE_PATTERNS": "*/tools/* */TESTS/* */targets/* */FEATURE_*/* */features/mbedtls/* */features/storage/* */features/unsupported/* */features/filesystem/* */BUILD/* */rtos/TARGET_CORTEX/rtx*/* */cmsis/* */features/FEATURES_*"
+    "EXCLUDE_PATTERNS": "*/tools/* */targets/* */FEATURE_*/* */features/mbedtls/* */features/storage/* */features/unsupported/* */features/filesystem/* */BUILD/* */rtos/TARGET_CORTEX/rtx*/* */cmsis/* */features/FEATURES_*"
 }