When CLPF was extended to chroma, the chroma RDO accidentally
discarded the optimal block size found in the luma RDO.

PSNR YCbCr:     -0.25%      0.05%      0.06%
   PSNRHVS:     -0.19%
      SSIM:     -0.36%
    MSSSIM:     -0.23%

Conflicts:
	av1/common/clpf.c

Change-Id: Ie49cd30f9276a311ada88cb2f13d14757617f030