drm/msm: fix allocation of dumb buffers for non-RGB formats

drm/msm: fix allocation of dumb buffers for non-RGB formats

Several users (including IGT kms_getfb tests) allocate DUMB buffers for
YUV data. Commit 538fa012cbdb ("drm/msm: Compute dumb-buffer sizes with
drm_mode_size_dumb()") broke that usecase, since in those cases
drm_driver_color_mode_format() returns DRM_FORMAT_INVALID.

Handle the YUV usecase, aligning to 32-bit pixels.

Fixes: 538fa012cbdb ("drm/msm: Compute dumb-buffer sizes with drm_mode_size_dumb()")
Closes: https://lore.kernel.org/all/vptw5tquup34e3jen62znnw26qe76f3pys4lpsal5g3czwev6y@2q724ibos7by/
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/685197/
Message-ID: <20251103-drm-msm-fix-nv12-v2-1-75103b64576e@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>