drm/mediatek: Add missing MODULE_DEVICE_TABLE()

This patch adds the missing MODULE_DEVICE_TABLE definitions on different
Mediatek drivers which generates correct modalias for automatic loading
when these drivers are compiled as an external module.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>