media: mediatek: vcodec: record capture queue format type

The capture queue format type may be differ depending on platform: for
stateless decoder drivers, we need to calculate the capture buffer size
according to the capture queue format type in SCP.

As a preparation for introducing drivers for stateless decoding, save the
current capture queue type on a per vcodec context basis.

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>