OMAP: DSS2: Clean up DISPC color mode validation checks

The supported set of color modes varies for different DISPC pipelines(plane)
and omap version. This makes the checks for validation of a color mode more
complicated as new omap versions are added.

A dss_feature function is created which tells if a color_mode is supported
for a plane on the current omap revision.

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
diff --git a/drivers/video/omap2/dss/dss_features.c b/drivers/video/omap2/dss/dss_features.c
index 854deba..620221f 100644
--- a/drivers/video/omap2/dss/dss_features.c
+++ b/drivers/video/omap2/dss/dss_features.c
@@ -179,6 +179,13 @@
 	return omap_current_dss_features->supported_color_modes[plane];
 }
 
+bool dss_feat_color_mode_supported(enum omap_plane plane,
+		enum omap_color_mode color_mode)
+{
+	return omap_current_dss_features->supported_color_modes[plane] &
+			color_mode;
+}
+
 /* DSS has_feature check */
 bool dss_has_feature(enum dss_feat_id id)
 {