Philippe Gorley authored Jun 07, 2017 and Adrien Béraud committed Jun 20, 2017

FFmpeg provides more hardware acceleration than libav for iOS

Since FFmpeg is now the default provider for libav*, remove all
the ifdef clauses. For platforms using libav, an ifdef should be
added to the rules.mak

Change-Id: I6f53bdf35b16803aa0a3f5aeda9c7c430cd0025d