stagefright: Add support for Exynos hardware audio decoding

This patch includes support for Exynos AAC and MP3 decoders.

The following edits are needed as well, but not included in this
commit because CM already had them:

1) http://review.cyanogenmod.org/#/c/105520/11/media/libstagefright/AudioPlayer.cpp (line 529)
2) http://review.cyanogenmod.org/#/c/105520/11/media/libstagefright/OMXCodec.cpp (line 3290)
3) http://review.cyanogenmod.org/#/c/105520/11/media/libstagefright/StagefrightMediaScanner.cpp (line 51)

Taken from Hardkernel:
https://github.com/codewalkerster/android_frameworks_av/commit/dcd507cdb113b939967247afa31cd777ea34c43d

Change-Id: I555100c4afb73b56485873976e5bdb6b0605c58b