Use long option flags for rgbgfx, same as tools/gfx

Makefile

@@ -210,14 +210,14 @@ gfx/pokemon/girafarig/front.animated.tilemap: gfx/pokemon/girafarig/front.2bpp g
 ### Pokemon and trainer sprite rules
 
 gfx/pokemon/%/back.2bpp: gfx/pokemon/%/back.png gfx/pokemon/%/normal.gbcpal
-	$(RGBGFX) -Z -c gbc:$(word 2,$^) -o $@ $<
+	$(RGBGFX) --columns --colors gbc:$(word 2,$^) -o $@ $<
 gfx/pokemon/%/front.2bpp: gfx/pokemon/%/front.png gfx/pokemon/%/normal.gbcpal
-	$(RGBGFX) -c gbc:$(word 2,$^) -o $@ $<
+	$(RGBGFX) --colors gbc:$(word 2,$^) -o $@ $<
 gfx/pokemon/%/normal.gbcpal: gfx/pokemon/%/front.gbcpal gfx/pokemon/%/back.gbcpal
 	tools/gbcpal $(tools/gbcpal) $@ $^
 
 gfx/trainers/%.2bpp: gfx/trainers/%.png gfx/trainers/%.gbcpal
-	$(RGBGFX) -Z -c gbc:$(word 2,$^) -o $@ $<
+	$(RGBGFX) --columns --colors gbc:$(word 2,$^) -o $@ $<
 
 
 ### Rules to match specific Pokemon and trainer sprites
@@ -240,12 +240,12 @@ gfx/trainers/swimmer_m.gbcpal: tools/gbcpal += --reverse
 
 # Egg does not have a back sprite, so it only uses front.gbcpal
 gfx/pokemon/egg/front.2bpp: gfx/pokemon/egg/front.png gfx/pokemon/egg/front.gbcpal
-gfx/pokemon/egg/front.2bpp: rgbgfx += -c gbc:$(word 2,$^)
+gfx/pokemon/egg/front.2bpp: rgbgfx += --colors gbc:$(word 2,$^)
 
 # Unown letters share one normal.pal, so they don't already build each normal.gbcpal
 $(foreach png, $(wildcard gfx/pokemon/unown_*/front.png),\
 	$(eval $(png:.png=.2bpp): $(png) $(png:front.png=normal.gbcpal)))
-gfx/pokemon/unown_%/front.2bpp: rgbgfx += -c gbc:$(@:front.2bpp=normal.gbcpal)
+gfx/pokemon/unown_%/front.2bpp: rgbgfx += --colors gbc:$(@:front.2bpp=normal.gbcpal)
 
 
 ### Misc file-specific graphics rules