drm/i915: More s/IS_IRONLAKE/HAS_PCH_SPLIT for Sandybridge.

I think this is pretty much correct.  Not really tested.

Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3fe9073..9cd6de5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -886,7 +886,7 @@
 	if (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)) {
 		int lvds_reg;
 
-		if (IS_IRONLAKE(dev))
+		if (HAS_PCH_SPLIT(dev))
 			lvds_reg = PCH_LVDS;
 		else
 			lvds_reg = LVDS;
@@ -3320,12 +3320,12 @@
 		/* set the dithering flag */
 		if (IS_I965G(dev)) {
 			if (dev_priv->lvds_dither) {
-				if (IS_IRONLAKE(dev))
+				if (HAS_PCH_SPLIT(dev))
 					pipeconf |= PIPE_ENABLE_DITHER;
 				else
 					lvds |= LVDS_ENABLE_DITHER;
 			} else {
-				if (IS_IRONLAKE(dev))
+				if (HAS_PCH_SPLIT(dev))
 					pipeconf &= ~PIPE_ENABLE_DITHER;
 				else
 					lvds &= ~LVDS_ENABLE_DITHER;