mdss: display: fix incorrect rotator programming

Source format should indicate that source is to be rotated 90 degrees
instead of indicating source has been rotated 90 degrees. This is needed
for hardware to fetch source in correct order and generate correct 90
degree output image.

Change-Id: If8d1e12ef3e7a291e67ec9763f5ca92ec6fa983c
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>