The 2-D inverse transform X = M1*Z*Transposed_M2 was calculated
in 2 steps from left to right:
1. Vertical transform: Y = M1*Z
2. Horizontal transform: X= Y*Transposed_M2
In SIMD, a transpose is needed in vertical transform.

Here, switched the calculation order to do it from right to left.
In this way, we could eliminate that transpose by writing the
intermediate results out to their transposed positions.

Change-Id: I34dfe5eb01292f6e363712420d99475e2e81e12c