media: i2c: ov5647: Use v4l2_async_register_subdev_sensor for lens binding

media: i2c: ov5647: Use v4l2_async_register_subdev_sensor for lens binding

v4l2_async_register_subdev doesn't bind in lens or flash drivers,
but v4l2_async_register_subdev_sensor does.
Switch to using v4l2_async_register_subdev_sensor.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>