Add gbafix from devkitPro/gba-tools

Makefile

@@ -43,6 +43,7 @@ MID := $(abspath tools/mid2agb/mid2agb)
 SCANINC := tools/scaninc/scaninc
 PREPROC := tools/preproc/preproc
 RAMSCRGEN := tools/ramscrgen/ramscrgen
+FIX := tools/gbafix/gbafix
 
 # Clear the default suffixes
 .SUFFIXES:
@@ -171,5 +172,5 @@ $(ELF): $(OBJ_DIR)/ld_script.ld $(OBJS)
 
 $(ROM): $(ELF)
 	$(OBJCOPY) -O binary $< $@
-	gbafix $@ -p -t"$(TITLE)" -c$(GAME_CODE) -m$(MAKER_CODE) -r$(REVISION)
+	$(FIX) $@ -p -t"$(TITLE)" -c$(GAME_CODE) -m$(MAKER_CODE) -r$(REVISION)