add RTGRAPHIC_PIXEL_FORMAT_COLOR to graphic deice

Signed-off-by: yangfasheng <yangfasheng@live.com>

include/rtdef.h

@@ -1020,6 +1020,7 @@ enum
     RTGRAPHIC_PIXEL_FORMAT_ABGR888,
     RTGRAPHIC_PIXEL_FORMAT_ARGB565,
     RTGRAPHIC_PIXEL_FORMAT_ALPHA,
+    RTGRAPHIC_PIXEL_FORMAT_COLOR,
 };
 
 /**