media: platform: mtk-mdp3: add support second sets of MUTEX

media: platform: mtk-mdp3: add support second sets of MUTEX

After setting up the second set of MMSYS (VPPSYS1), it is necessary
to have a corresponding second set of MUTEX (MUTEX2) to assist in
handling SOF/EOF.

Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Sebastian Fricke <sebastian.fricke@collabora.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>