changed loop filter for MBs using 8x8 transform

This commit added a set of loop filter functions for macroblocks
using 8x8 transform. First we turned off the regular loop filtering
on 4x4 block boundaries that do not exist in macroblocks using 8x8
transform. Second, we change to use the same loop filter(mask and
7 tap filter) that used for macroblock edge filtering.

Change-Id: I3a00460b7674ced116917d86812ffc32578c1d3a