hwc:Change the flip value in case of MDP3.0 based target.

When flip and rotation(90) are present alter the flip,
as GPU is doing the flip and rotation in opposite order
to that of MDP3.0
For 270 degrees, we get 90 + (H+V) which is same as doing
flip first and then rotation (H+V) + 90

Change-Id: Ia4e7117e94e4ef76c6c771c172173c41edbd4d2c