media: i2c: imx219: Use subdev active state

Port the imx219 sensor driver to use the subdev active state.

Move all the format configuration to the subdevice state and simplify
the format handling, locking and initialization.

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>