drm/fourcc: Add DRM_FORMAT_XYYY2101010

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>