[media] coda: split out encoder control setup to specify controls per video device

This patch splits the encoder specific controls out of the main control setup
function. This way each video device registers only relevant controls.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>