drm/i915: Drop WaDoubleCursorLP3Latency:ivb

WaDoubleCursorLP3Latency was meant for pre-production hardware.
Drop it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180130203807.13721-6-ville.syrjala@linux.intel.comReviewed-by: Mika Kahola <mika.kahola@intel.com>

drivers/gpu/drm/i915/intel_pm.c

@@ -2917,10 +2917,6 @@ static void intel_fixup_cur_wm_latency(struct drm_i915_private *dev_priv,
 	/* ILK cursor LP0 latency is 1300 ns */
 	if (IS_GEN5(dev_priv))
 		wm[0] = 13;
-
-	/* WaDoubleCursorLP3Latency:ivb */
-	if (IS_IVYBRIDGE(dev_priv))
-		wm[3] *= 2;
 }
 
 int ilk_wm_max_level(const struct drm_i915_private *dev_priv)