Make sure only the planes on the active CRTCs get committed and
that all planes on the disabled CRTCs get turned off.
Reviewed-by: NBrian Starkey <brian.starkey@arm.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: NLiviu Dudau <liviu.dudau@arm.com>