media: i2c: ov5645: Call ov5645_entity_init_cfg() before registering the subdev

Make sure we call ov5645_entity_init_cfg() before registering the subdev
to make sure default formats are set up.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.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>