Add a V4L2 sub-device driver for Omnivision og01a1b b&w
image sensor. This is a camera sensor using the I2C bus
for control and the CSI-2 bus for data.

This driver supports following features:
- manual exposure and analog/digital gain control support
- vblank/hblank control support
- test pattern support
- media controller support
- runtime PM support
- support following resolutions:
  + 1280x1024 at 120FPS
Signed-off-by: Shawn Tu <shawnx.tu@intel.com>
[Sakari Ailus: Update according to recent v4l2-async API changes]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>