media: adv7604: add CEC support for adv7611/adv7612

The CEC IP is very similar between the three HDMI receivers, but
not identical. Add support for all three variants.

Tested with an adv7604 and an adv7612.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>