Add a driver for OmniVision OV8858 image sensor.

The driver currently supports operations with 2 and 4 data lanes, in
full resolution and half-binned resolution modes.

The driver has been upported from the PinephonePro BSP available at
https://gitlab.com/pine64-org/linux.git
at commit 8c4a90c12dc2 ("media: i2c: ov8858: Use default subdev
name").
Signed-off-by: Nicholas Roth <nicholas@rothemail.net>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>