[media] cec: move the CEC framework out of staging and to media
The last open issues have been addressed, so it is time to move this out of staging and into the mainline and to move the public cec headers to include/uapi/linux. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>