media: ov5640: Remove ov5640_mode_init_data

The ov5640_mode_init_data is a fictional sensor more which is used to
program the initial sensor settings.

It is only used to initialize the sensor and can be replaced
it with a throw-away mode which just wraps the register table.

Also rename the register table to drop the format from the name to make
it clear an actual sensor mode has to be applied after the initial
programming.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
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>