base

CEC: Buffer <Set System Audio Mode>

<Set System Audio Mode> is another command that needs to be buffered
in case the command arrives before the system is ready to process it.
When processed, system audio mode will be enabled based on the
global setting.

Bug: 18809965

Change-Id: Ia6ebc4e2919e1b94498ca28f652c6db95f907f9c