fix make dep with some gcc versions

Originally committed as revision 6988 to svn://svn.ffmpeg.org/ffmpeg/trunk

Makefile

@@ -208,7 +208,7 @@ ifeq ($(CONFIG_VHOOK),yes)
 endif
 
 .depend: $(SRCS) version.h
-	$(CC) -MM $(CFLAGS) $(SDL_CFLAGS) $^ 1>.depend
+	$(CC) -MM $(CFLAGS) $(SDL_CFLAGS) $(filter-out %.h,$^) 1>.depend
 
 .libs: lib
 	@test -f .libs || touch .libs