V4L/DVB (10669): ov772x: Add image flip support

o ov772x_camera_info :: flags supports default image flip.
o V4L2_CID_VFLIP/HFLIP supports image flip for user side.
Thank Magnus for advice.

Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>