[CEC] bump libCEC to 2.2.0
[CEC] prevent bus rescan on a Pi, since the adapter cannot be removed
[CEC] fixed: don't return garbage from CEC related app messenger methods
see https://github.com/xbmc/xbmc/commit/19d37944ca2a2ac2f3e71a40a94e9ea289d8f2db#commitcomment-8248480
[CEC] renamed the iDoubleTapTimeoutMs in the new libCEC for clarity. does not change binary compatibility