media: verisilicon: Hook the (TRY_)DECODER_CMD stateless ioctls

[ Upstream commit 6c0d9e12 ]

The (TRY_)DECODER_CMD ioctls are used to support flushing when holding
capture buffers is supported. This is the case of this driver but the
ioctls were never hooked to the ioctl ops.

Add them to correctly support flushing.

Fixes: 340ce50f ("media: hantro: Enable HOLD_CAPTURE_BUF for H.264")
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>