media: dt-bindings: Add ch7322 media i2c device

The ch7322 is a Chrontel CEC controller.

Signed-off-by: Jeff Chase <jnchase@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>