Add DT entries for vin0, vin0_pins, and adv7612.

Sets the 'default-input' property for ADV7612, enabling image and video
capture without the need to have userspace specifying routing.
Signed-off-by: William Towle <william.towle@codethink.co.uk>
Signed-off-by: Rob Taylor <rob.taylor@codethink.co.uk>
[uli: added interrupt, renamed endpoint, merged default-input]
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>