media: vicodec: allow en/decoder cmd w/o CAPTURE

Vicodec will ignore en/decoder commands if the CAPTURE queue is not
streaming. But this prevents CMD_STOP from being used during a dynamic
resolution change to mark the last source buffer. Since CMD_STOP is
ignored, but doesn’t fail, there is no warning that the command needs to
be resent, and CAPTURE will continue to attempt to dequeue buffers
waiting, futilely, for one with V4L2_BUF_FLAG_LAST.

Fix this problem by carrying out en/decoder commands even if CAPTURE is
not streaming.

Fixes: d17589af vicodec: improve handling of ENC_CMD_STOP/START
Reported by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Signed-off-by: Sebastian Fricke <sebastian.fricke@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>