media: ov5640: Remove duplicated mode settings

The register tables for all resolutions smaller than 720p are now
identical.

Remove the duplicated ones and create a single ov5640_setting_low_res[]
register table.

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>