Reduce loop filter in cyclic refresh.
Reduce the delta loop filter for blocks that are cyclicly refreshed. This helps to reduce the dot artifacts that may happen when zero_mv blocks are repeatedly loop-filtered. This change, along with the fix in: https://gerrit.chromium.org/gerrit/#/c/40409/ helps to reduce this artifact, but cannot remove the dot artifacts completely. Change-Id: I44675e7a0f59295b648a3b7d4956fb301231a97f