libstagefright: back off exynos4 hacks

Change-Id: I953f502171bc98854b5d59165057c57b3c65cdaa
libstagefright: align YV12 for software codecs on exynos4

YV12 chroma stide should be aligned to 16 according to the
android framework. But, GSC & Mali couldn't accept a seperate
stride for U & V components. They just use Y_stride/2 as a
UV Stride.

Change-Id: Ibeeb3439ee10a4666420e5fa34ff0a6d6ea7c003
libstagefright: fix YV12 stride for software codecs on exynos4

Change-Id: I3612899d2bffa474eb6447788858911757a7f45d
omx: exynos4: bring inline with jellybean

Change-Id: Ic275fd30a721f8161dcc44c2706b86ab5ea213ba