[media] vivid: use new v4l2-rect.h header

The v4l2_rect helper functions have been moved to
include/media/v4l2-rect.h. Use this new header, dropping the functions
from vivid.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>