Revert "Exynos decoder: workaround for wrong MFC output format."

This reverts r226912 (commit 1d07393296ba6e33eb398cc0e02077aa61fb2ccd).

The corruption is now fixed with a new version of the MFC firmware.

BUG=chrome-os-partner:23078
TEST=Verify that crbug.com/302870 does not reproduce anymore

Review URL: https://codereview.chromium.org/47553003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231412 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231412