drm/i915/cfl: Fix Workarounds.

During the review of Coffee Lake workarounds Mika pointed out
that WaDisableKillLogic and GEN9_DISABLE_OCL_OOB_SUPPRESS_LOGIC
should be removed from CFL and with that I should carry the rv-b.

However when doing the v2 I removed another Workaround that should
remain because although not mentioned by spec the history of hangs
around it advocates on its favor.

On some follow-up patches I continued operating on the wrong
workardound, but Ville noticed that, so here is the fix for the
current CFL code that is upstream already.

Fixes: 46c26662d2 ("drm/i915/cfl: Introduce Coffee Lake workarounds.")
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

drivers/gpu/drm/i915/intel_engine_cs.c

@@ -809,9 +809,10 @@ static int gen9_init_workarounds(struct intel_engine_cs *engine)
 	I915_WRITE(BDW_SCRATCH1, I915_READ(BDW_SCRATCH1) |
 		   GEN9_LBS_SLA_RETRY_TIMER_DECREMENT_ENABLE);
 
-	/* WaDisableKillLogic:bxt,skl,kbl,cfl */
-	I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) |
-		   ECOCHK_DIS_TLB);
+	/* WaDisableKillLogic:bxt,skl,kbl */
+	if (!IS_COFFEELAKE(dev_priv))
+		I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) |
+			   ECOCHK_DIS_TLB);
 
 	/* WaClearFlowControlGpgpuContextSave:skl,bxt,kbl,glk,cfl */
 	/* WaDisablePartialInstShootdown:skl,bxt,kbl,glk,cfl */
@@ -882,10 +883,9 @@ static int gen9_init_workarounds(struct intel_engine_cs *engine)
 	WA_SET_BIT_MASKED(HDC_CHICKEN0,
 			  HDC_FORCE_NON_COHERENT);
 
-	/* WaDisableHDCInvalidation:skl,bxt,kbl */
-	if (!IS_COFFEELAKE(dev_priv))
-		I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) |
-			   BDW_DISABLE_HDC_INVALIDATION);
+	/* WaDisableHDCInvalidation:skl,bxt,kbl,cfl */
+	I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) |
+		   BDW_DISABLE_HDC_INVALIDATION);
 
 	/* WaDisableSamplerPowerBypassForSOPingPong:skl,bxt,kbl,cfl */
 	if (IS_SKYLAKE(dev_priv) ||