media: ov5640: fix vblank unchange issue when work at dvp mode

The value of V4L2_CID_VBLANK control is initialized to default vblank
value of 640x480 when driver probe. When OV5640 work at DVP mode, the
control value won't update and lead to sensor can't output data if the
resolution remain the same as last time since incorrect total vertical
size. So update it when there is a new value applied.

Fixes: bce93b82

 ("media: ov5640: Add VBLANK control")
Signed-off-by: Guoniu.zhou <guoniu.zhou@nxp.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>