[media] omap3isp: Mark the resizer output video node as the default video node

The resizer can output YUYV and UYVY in a wide range of sizes, making it
the best video node for regular V4L2 applications.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>