This optimization for speed was useful only when max tx-size
was 32x32. However with tx64x64 this was breaking certain assumptions
causing huge drops in coding efficiency. So I am removing this
optimization for now. This can be brought back latger as a speed feature.
The removal of this optimzation brings back the loss when 32x64
and 64x32 transforms are used.

Change-Id: I15987ea9ff53fa36a2962fe5f156c30a11e809ed