media: seco-cec: add Consumer-IR support

Introduce support for Consumer-IR into seco-cec driver, as it shares the
same interrupt for receiving messages.
The device decodes RC5 signals only, defaults to hauppauge mapping.
It will spawn an input interface using the RC framework (like CEC
device).

Signed-off-by: Ettore Chimenti <ek5.chimenti@gmail.com>
Reviewed-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>