Needed for multihead setups where we can have disabled
outputs and therefore plane->crtc can be NULL.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1464609806-22013-1-git-send-email-kraxel@redhat.com