Update Makefile.libretro (#355)

Makefile.libretro

@@ -383,7 +383,7 @@ else ifneq (,$(filter $(platform), ngc wii wiiu))
    AR = $(DEVKITPPC)/bin/powerpc-eabi-ar$(EXE_EXT)
 	ENDIANNESS_DEFINES := -DBYTE_ORDER=BIG_ENDIAN -DCPU_IS_BIG_ENDIAN=1 -DWORDS_BIGENDIAN=1
    PLATFORM_DEFINES := -DGEKKO -mcpu=750 -meabi -mhard-float -DALT_RENDER
-   PLATFORM_DEFINES += -U__INT32_TYPE__ -U __UINT32_TYPE__ -D__INT32_TYPE__=int
+   PLATFORM_DEFINES += -ffunction-sections -fdata-sections -D__wiiu__ -D__wut__
    STATIC_LINKING = 1
    USE_PER_SOUND_CHANNELS_CONFIG = 0