media: ov5640: Change horizontal and vertical resolutions name

The current width and height parameters in the struct ov5640_mode_info are
actually the active horizontal and vertical resolutions.

Since we're going to add a few other parameters, let's pick a better, more
precise name for these values.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>