Adds a driver for the 12MPix Sony IMX477 CSI2 sensor.
Whilst the sensor supports 2 or 4 CSI2 data lanes, this driver
currently only supports 2 lanes.

The following Bayer modes are currently available:

4056x3040 12-bit @ 10fps
2028x1520 12-bit (binned) @ 40fps
2028x1050 12-bit (cropped/binned) @ 50fps
1012x760 10-bit (scaled) @ 120 fps

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>