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/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index f93f822..5388354 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -166,7 +166,7 @@
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 
-	if (IS_IRONLAKE(dev))
+	if (HAS_PCH_SPLIT(dev))
 		ironlake_enable_display_irq(dev_priv, DE_GSE);
 	else
 		i915_enable_pipestat(dev_priv, 1,