legacy OMX: move legacy mmparser under a different flag before removing the code completely. Just use libExtendedExtractor instead. Turns out it doesn't do much other than dlopen mmparser.

Change-Id: I268024789ffcd46634fea71fdb287b6a762fe34d
Merge "legacy OMX: move legacy mmparser under a different flag before removing the code completely. Just use libExtendedExtractor instead. Turns out it doesn't do much other than dlopen mmparser." into pac-4.4