media: mediatek: vcodec: Fix non subdev architecture open power fail

According to subdev_bitmap bit value to open hardware power, need to
set subdev_bitmap value for non subdev architecture.

Fixes: c05bada3

 ("media: mtk-vcodec: Add to support multi hardware decode")
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>