Change to fourcc to enable decoding of ffmpeg files.

Change-Id: Ia16f167d904d53bc38cb3a8c841c6c52daad500f
(cherry picked from commit 296421d84cd1ffd074ff3fe4a772238c897f1bda)
reverts: dbd050c vpxdec: correct VP[89] fourccs
1 file changed