drm/fourcc: Add DRM_FORMAT_XYYY2101010

Add XYYY2101010 ("YPA4"), a 10 bit greyscale format, with 3 pixels
packed into 32-bit container, and two bits of padding.

The fourcc for the format is 'YPA4', which comes from Y - Y only, P -
packed, A - 10 (as in 0xA), 4 - 4 bytes.

Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Link: https://patch.msgid.link/20260423-xilinx-formats-v10-4-c690c2b8ea89@ideasonboard.com
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

drivers/gpu/drm/drm_fourcc.c

@@ -385,6 +385,9 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_S416,            .depth = 0,  .num_planes = 3,
 		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
 		  .hsub = 1, .vsub = 1, .is_yuv = true},
+		{ .format = DRM_FORMAT_XYYY2101010,	.depth = 0,  .num_planes = 1,
+		  .char_per_block = { 4, 0, 0 }, .block_w = { 3, 0, 0 }, .block_h = { 1, 0, 0 },
+		  .hsub = 1, .vsub = 1, .is_yuv = true },
 	};
 
 	unsigned int i;

include/uapi/drm/drm_fourcc.h

@@ -450,6 +450,7 @@ extern "C" {
  */
 
 #define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
+#define DRM_FORMAT_XYYY2101010	fourcc_code('Y', 'P', 'A', '4')  /* [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian */
 
 /*
  * Format Modifiers: