media: coda: fail S_SELECTION for read-only targets

v4l2-compliance complains if S_SELECTION returns 0 for read-only targets.

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