Add some helper functions to move drm_rects between different rotated
coordinate spaces. One function does the forward transform and
another does the inverse.
Cc: dri-devel@lists.freedesktop.org Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Imre Deak <imre.deak@intel.com> Acked-by: Dave Airlie <airlied@linux.ie> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>