Enable warning for unused static functions

Author: jepler

ports/raspberrypi/Makefile

@@ -198,7 +198,7 @@ else
 endif
 
 # Remove -Wno-stringop-overflow after we can test with CI's GCC 10. Mac's looks weird.
-DISABLE_WARNINGS = -Wno-stringop-overflow -Wno-unused-function -Wno-unused-variable -Wno-strict-overflow -Wno-cast-align -Wno-strict-prototypes -Wno-nested-externs -Wno-double-promotion -Wno-sign-compare
+DISABLE_WARNINGS = -Wno-stringop-overflow -Wno-unused-variable -Wno-strict-overflow -Wno-cast-align -Wno-strict-prototypes -Wno-nested-externs -Wno-double-promotion -Wno-sign-compare
 
 CFLAGS += $(INC) -Wall -Werror -std=gnu11 -nostdlib -fshort-enums $(BASE_CFLAGS) $(CFLAGS_MOD) $(COPT) $(DISABLE_WARNINGS) -Werror=missing-prototypes
 
@@ -256,7 +256,7 @@ SRC_SDK := \
 	$(SRC_SDK_CYW43) \
 
 SRC_SDK := $(addprefix sdk/, $(SRC_SDK))
-$(patsubst %.c,$(BUILD)/%.o,$(SRC_SDK) $(SRC_CYW43)): CFLAGS += -Wno-missing-prototypes -Wno-undef
+$(patsubst %.c,$(BUILD)/%.o,$(SRC_SDK) $(SRC_CYW43)): CFLAGS += -Wno-missing-prototypes -Wno-undef -Wno-unused-function
 
 SRC_C += \
 	boards/$(BOARD)/board.c \