[media] coda: only set buffered input queue for decoder

Allow device_run with no buffers queued after streamoff only when
the current instance is a decoder.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
[k.debski@samsung.com: Add commit description]
Signed-off-by: Kamil Debski <k.debski@samsung.com>

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>