media: i2c: ov9282: Reduce vblank_min values based on testing

The configured vblank_min setting of 151 (meaning VTS of
720 + 151 = 871) is far higher than the setting that works on
the sensor, and there are no obvious restrictions stated in the
datasheet.

Reduce the vblank_min to allow for faster frame rates.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>