host1x: drm: Use XBGR8888 pixel format
host1x: drm: Use XBGR8888 pixel format

This seems to be the default pixel format that the gr3d engine uses to
render. Mark framebuffers as using that format so they will be correctly
scanned-out by the display controller.

Signed-off-by: Thierry Reding <819d67e53b6c9983dea118cea592f5214247b065@gilfi.de>

grate-driver/grate,digetx/grate,digetx/grate,grate-driver/grate