media: marvell-ccic: add support for runtime PM

On MMP3, the camera block lives on a separate power island. We want to
turn it off if the CCIC is not in use to conserve power.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>