libvpx

Change speed features for good quality(cpu-used=5)

The existing speed features produce horrible encoding results, almost
30% worse than cpu-used=4, this commit adjust the speed features to
produce relatively resonable results to be within 3%-5% of cpu-used=4.

Change-Id: I0ca6ebafb33024d4a0cbcf04c78a4a00b8dd1ecf