[media] media: adv7604: chip info and formats for ADV7612

Add support for the ADV7612 chip as implemented on Renesas' Lager
board to adv7604.c, including lists for formats/colourspace/timing
selection and an IRQ handler.

Signed-off-by: William Towle <william.towle@codethink.co.uk>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
[hans.verkuil@cisco.com: fix merge conflicts due to regmap patch]

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>