drm/vc4: plane: Add support for DRM_FORMAT_P030

The P030 format, used with the DRM_FORMAT_MOD_BROADCOM_SAND128 modifier,
is a format output by the video decoder on the BCM2711.

Add native support to the KMS planes for that format.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20211215091739.135042-3-maxime@cerno.tech