media: coda: disable encoder command on decoder and vice versa

Return -ENOTTY when userspace tries to call VIDIOC_(TRY_)ENCODER_CMD on
a decoder instance or VIDIOC_(TRY_)DECODER_CMD on an encoder instance.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>