[media] coda: Improve runtime PM support

For several reasons it's good practice to leave devices in runtime PM
active state while those have been probed.

In this cases we also want to prevent the device from going inactive,
until the firmware has been completely installed, especially when using
a PM domain.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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>