drm/i915: make the panel fitter work on pipes B and C on Haswell

This goes on a separate patch since it won't apply on the stable
trees and there's nothing using panel fitter on HSW on the older
Kernels.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -3467,7 +3467,8 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
 		 * as some pre-programmed values are broken,
 		 * e.g. x201.
 		 */
-		I915_WRITE(PF_CTL(pipe), PF_ENABLE | PF_FILTER_MED_3x3);
+		I915_WRITE(PF_CTL(pipe), PF_ENABLE | PF_FILTER_MED_3x3 |
+					 PF_PIPE_SEL_IVB(pipe));
 		I915_WRITE(PF_WIN_POS(pipe), dev_priv->pch_pf_pos);
 		I915_WRITE(PF_WIN_SZ(pipe), dev_priv->pch_pf_size);
 	}