drm/mediatek: Add AFBC support to Mediatek DRM driver

Tested on MT8195 and confirmed both correct video output and improved DRAM
bandwidth performance.

Signed-off-by: Justin Green <greenjustin@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20221116193335.36320-1-greenjustin@google.com/


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