[media] V4L: ov9650: fix control clusters

Auto-gain and auto-exposure clusters in the ov9650 driver have both a
size of 2, not 3 controls. Fix this.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>