drm: Fix EDID color format parsing

The code should obviously check the EDID feature field for EDID feature flags
and not the color_formats field of the drm_display_info struct. Also update the
color_formats field with new modes instead of overwriting the current mode.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_edid.c

@@ -1699,10 +1699,10 @@ static void drm_add_display_info(struct edid *edid,
 	}
 
 	info->color_formats = DRM_COLOR_FORMAT_RGB444;
-	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB444)
-		info->color_formats = DRM_COLOR_FORMAT_YCRCB444;
-	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB422)
-		info->color_formats = DRM_COLOR_FORMAT_YCRCB422;
+	if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB444)
+		info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
+	if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB422)
+		info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
 
 	/* Get data from CEA blocks if present */
 	edid_ext = drm_find_cea_extension(edid);