This is the reST migration of media's CEC part. The migration is based
on media_tree's cec branch:
https://git.linuxtv.org/media_tree.gitc7169ad * cec media_tree/cec [media] DocBook/media: add CEC documentation
Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>