drm: add fourcc codes for 16bit R and RG

This adds fourcc codes for 16bit planes required for DRM buffer
export to mesa.

Signed-off-by: Rainer Hochecker <fernetmenta@online.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20170104183855.3852-1-fernetmenta@kodi.tv
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

include/uapi/drm/drm_fourcc.h

@@ -41,10 +41,17 @@ extern "C" {
 /* 8 bpp Red */
 #define DRM_FORMAT_R8		fourcc_code('R', '8', ' ', ' ') /* [7:0] R */
 
+/* 16 bpp Red */
+#define DRM_FORMAT_R16		fourcc_code('R', '1', '6', ' ') /* [15:0] R little endian */
+
 /* 16 bpp RG */
 #define DRM_FORMAT_RG88		fourcc_code('R', 'G', '8', '8') /* [15:0] R:G 8:8 little endian */
 #define DRM_FORMAT_GR88		fourcc_code('G', 'R', '8', '8') /* [15:0] G:R 8:8 little endian */
 
+/* 32 bpp RG */
+#define DRM_FORMAT_RG1616	fourcc_code('R', 'G', '3', '2') /* [31:0] R:G 16:16 little endian */
+#define DRM_FORMAT_GR1616	fourcc_code('G', 'R', '3', '2') /* [31:0] G:R 16:16 little endian */
+
 /* 8 bpp RGB */
 #define DRM_FORMAT_RGB332	fourcc_code('R', 'G', 'B', '8') /* [7:0] R:G:B 3:3:2 */
 #define DRM_FORMAT_BGR233	fourcc_code('B', 'G', 'R', '8') /* [7:0] B:G:R 2:3:3 */