media: ov5640: Enhance FPS handling

Now that we have moved the clock generation logic out of the bytes array,
these arrays are identical between the 15fps and 30fps variants.

Remove the duplicate entries, and convert the code accordingly.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Adam Ford <aford173@gmail.com> #imx6dq
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>