media: mediatek: vcodec: Initialize decoder parameters after getting dec_capability

Need to get dec_capability from scp first, then initialize decoder
supported format and other parameters according to dec_capability value.

Fixes: fd00d903 ("media: mtk-vcodec: vdec: move stateful ops into their own file")
Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>