drm/i915: split PCH clock gating init

Ibex Peak and CougarPoint already require a different setting (added
here), and future chips will likely follow that precedent.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 6cb27ff..60a94d2 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -863,8 +863,7 @@
 		I915_WRITE(IMR, dev_priv->saveIMR);
 	}
 
-	/* Clock gating state */
-	dev_priv->display.init_clock_gating(dev);
+	intel_init_clock_gating(dev);
 
 	if (IS_IRONLAKE_M(dev)) {
 		ironlake_enable_drps(dev);