media: mt9m114: Fix default hblank and vblank values

media: mt9m114: Fix default hblank and vblank values

The current default hblank and vblank values are based on reaching 30 fps
with the pixel-array outputting 1280x960, but the default format for
the pixel-array source pad and the isp sink pad is 1296x976, correct
the default hblank and vblank values to take this into account.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>