Add a v4l2 sub-device driver for the Sony imx412 image sensor.
This is a camera sensor using the i2c bus for control and the
csi-2 bus for data.

The following features are supported:
- manual exposure and analog gain control support
- vblank/hblank/pixel rate/link freq control support
- supported resolution:
    - 4056x3040 @ 30fps
- supported bayer order output:
    - SRGGB10

[Sakari Ailus: Rebase on commit c802a4174beeb25cb539c806c9d0d3c0f61dfa53.]
Signed-off-by: NMartina Krasteva <martinax.krasteva@intel.com>
Acked-by: NDaniele Alessandrelli <daniele.alessandrelli@intel.com>
Acked-by: NPaul J. Murphy <paul.j.murphy@intel.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>