media: i2c: imx290: Add crop selection targets support

Implement read-only access to crop selection rectangles to expose the
analogue crop rectangle. The public (leaked) IMX290 documentation is not
very clear on how cropping is implemented and configured exactly, so
the margins may not be entirely accurate.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>