media: cec: document CEC_ADAP_G_CONNECTOR_INFO and capability

Document the new CEC_ADAP_G_CONNECTOR_INFO ioctl and the new
CEC_CAP_CONNECTOR_INFO capability.

Co-developed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Signed-off-by: Dariusz Marcinkiewicz <darekm@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: added CEC_CAP_CONNECTOR_INFO]
[hverkuil-cisco@xs4all.nl: added DQEVENT have_conn_info]
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>