FROMGIT: drm/mediatek: Register vblank callback function

Some ddp component exist in both display path and other path, so
sub driver should not directly call crtc function. crtc register
callback function to sub driver to prevent sub driver directly
call crtc function.

Signed-off-by: CK Hu <ck.hu@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

(cherry picked from commit 9b0704988b151824a51133dc4c921f4273c5d839
https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git mediatek-drm-next)

BUG=b:178064928
TEST=emerge-kukui chromeos-kernel-5_10

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Change-Id: Ia6d67368f76cea7734972f6bbeeb7332584107ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2641942
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2644666
5 files changed