drm/i915: WaDisableRHWOOptimizationForRenderHang isn't applicable to HSW

Can't find WaDisableRHWOOptimizationForRenderHang listed for HSW.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4770,10 +4770,6 @@ static void haswell_init_clock_gating(struct drm_device *dev)
 	 */
 	I915_WRITE(GEN6_UCGCTL2, GEN6_RCZUNIT_CLOCK_GATE_DISABLE);
 
-	/* Apply the WaDisableRHWOOptimizationForRenderHang:hsw workaround. */
-	I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
-		   GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC);
-
 	/* WaApplyL3ControlAndL3ChickenMode:hsw */
 	I915_WRITE(GEN7_L3CNTLREG1,
 			GEN7_WA_FOR_GEN7_L3_CONTROL);