drm/mediatek: backport v5.4 dpi driver

Backport 3 commits
874e976803e0dc6a649a89b7de45d5ba8d5c9030
9d1b0f4859ee22a670c2808548a96a42e4abc19d
1b056221cb8c3b9e5db5c591ca5927f124708ded

Signed-off-by: Phong LE <ple@baylibre.com>
1 file changed