Adjust speed features for 4k video encoding
Adjust speed features for 4k video encoding

Adjusted speed 2 features to speed up 4k video encoding.
BDBR results from borg test:
PSNR: +0.313%; SSIM: +0.268%.
Average speedup: 8.5%

Change-Id: I1e2695a01fb3f3817c1df4480e184c2aed8f2eba

mwgoldsmith/libvpx,mwgoldsmith/vpx,Topopiccione/libvpx,mwgoldsmith/libvpx,mwgoldsmith/libvpx,webmproject/libvpx,mwgoldsmith/vpx,ShiftMediaProject/libvpx,mwgoldsmith/vpx,webmproject/libvpx,ShiftMediaProject/libvpx,Topopiccione/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,mwgoldsmith/libvpx,webmproject/libvpx,mwgoldsmith/vpx,Topopiccione/libvpx,mwgoldsmith/libvpx,mwgoldsmith/vpx,mwgoldsmith/libvpx,Topopiccione/libvpx,mwgoldsmith/vpx,ShiftMediaProject/libvpx,Topopiccione/libvpx,ShiftMediaProject/libvpx,Topopiccione/libvpx,ShiftMediaProject/libvpx