msm8960-common: Enable use of FFMPEG codecs for extended formats

Change-Id: Ic95041cba31c084cbee321f581261f5a64dd4f53
msm8960-common: remove unused (and incorrect) flag

* TARGET_ARCH_VARIANT_CPU is only used for armv6
* TARGET_USE_KRAIT_BIONIC_OPTIMIZATION is deprecated

Change-Id: I1958199076b4e7b5be37f77260c819d814de9c69
media_codecs: Remove mpeg4/h263/h264 ffmpeg entries

Change-Id: Ibb99999c68e76ace28be848018cee737602d98eb