fbdev: generated logo sources depend on scripts/pnmtologo

The generated logo sources are not automatically regenerated if
scripts/pnmtologo.c has changed. Add the missing dependency to fix this.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/logo/Makefile b/drivers/video/logo/Makefile
index b91251d..3b43781 100644
--- a/drivers/video/logo/Makefile
+++ b/drivers/video/logo/Makefile
@@ -37,22 +37,24 @@
 # Gray 256
 extra-y += $(call logo-cfiles,_gray256,pgm)
 
+pnmtologo := scripts/pnmtologo
+
 # Create commands like "pnmtologo -t mono -n logo_mac_mono -o ..."
 quiet_cmd_logo = LOGO    $@
-	cmd_logo = scripts/pnmtologo \
+	cmd_logo = $(pnmtologo) \
 			-t $(patsubst $*_%,%,$(notdir $(basename $<))) \
 			-n $(notdir $(basename $<)) -o $@ $<
 
-$(obj)/%_mono.c: $(src)/%_mono.pbm FORCE
+$(obj)/%_mono.c: $(src)/%_mono.pbm $(pnmtologo) FORCE
 	$(call if_changed,logo)
 
-$(obj)/%_vga16.c: $(src)/%_vga16.ppm FORCE
+$(obj)/%_vga16.c: $(src)/%_vga16.ppm $(pnmtologo) FORCE
 	$(call if_changed,logo)
 
-$(obj)/%_clut224.c: $(src)/%_clut224.ppm FORCE
+$(obj)/%_clut224.c: $(src)/%_clut224.ppm $(pnmtologo) FORCE
 	$(call if_changed,logo)
 
-$(obj)/%_gray256.c: $(src)/%_gray256.pgm FORCE
+$(obj)/%_gray256.c: $(src)/%_gray256.pgm $(pnmtologo) FORCE
 	$(call if_changed,logo)
 
 # Files generated that shall be removed upon make clean