media: s5p-cec: use cec_notifier_cec_adap_(un)register

Use cec_notifier_cec_adap_(un)register instead of
cec_notifier_get, cec_notifier_put and cec_register_cec_notifier.

Also enable the CEC_CAP_CONNECTOR_INFO capability.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Sylwester Nawrocki <snawrocki@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>