v2: Don't forget to actually check the cstate->active value when
    tallying up the number of active CRTC's.  (Ander)
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>