Use YUV components to build the temporal filter

Use YUV components to build the temporal filter

Use both luma and chroma components simultaneously to estimate the
non-local mean kernel and build the temporal filter. It improves
the compression performance primarily for chroma components. Tested
in speed 0 and vbr mode, the coding gains are:

          Overall PSNR   SSIM     PSNR_U      PSNR_V
low        -0.10%       -0.12%    -0.48%      -0.49%
mid        -0.13%       -0.16%    -0.58%      -0.88%
720p       -0.31%       -0.24%    -0.75%      -0.72%
hd         -0.09%       -0.10%    -0.59%      -0.79%
nefl2k     -0.30%       -0.13%    -0.53%      -0.50%

Change-Id: I24d39997818322b0d69bd9dbeda02c60cd2b2e1b