[media] V4L: soc-camera: start removing struct soc_camera_device from client drivers

Remove most trivial uses of struct soc_camera_device from most client
drivers, abstracting some of them inside inline functions. Next steps
will eliminate remaining uses and modify inline functions to not use
struct soc_camera_device.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>