overlay: Account for transform in size calculation

If we have a transform of 90, we need to swap the width and
height in the origWhf to make sure we get the right size
calculation of the output buffer with all alignment requirements.

Change-Id: I90f4da9cf7d9c56a43058f99c6d406a72e1d3efc

Conflicts:
	liboverlay/overlayMdpRot.cpp