V4L/DVB (13659): soc-camera: convert to the new mediabus API

Convert soc-camera core and all soc-camera drivers to the new mediabus
API. This also takes soc-camera client drivers one step closer to also be
usable with generic v4l2-subdev host drivers.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>