drm/i915: Drop WaRsForcewakeWaitTC0:vlv

GEN6_GT_THREAD_STATUS_REG doesn't seem to exist on VLV. Reads just give
0x0 no matter what the state of the render and media wells.

There was also some hint in the Gunit HAS that thread status not being
needed on VLV, and hence dropped when bringing stuff over from the IVB
design. Not really a definite comment about the specific register itself
though.

Also the w/a itself is no longer listed for VLV in the database. It was
there some time ago in the past, but I guess someone figured out the
mistake and dropped it.

So let's just drop it from the code as well.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_uncore.c

@@ -222,10 +222,6 @@ static void __vlv_force_wake_get(struct drm_i915_private *dev_priv,
 					FORCEWAKE_ACK_TIMEOUT_MS))
 			DRM_ERROR("Timed out: waiting for media to ack.\n");
 	}
-
-	/* WaRsForcewakeWaitTC0:vlv */
-	if (!IS_CHERRYVIEW(dev_priv->dev))
-		__gen6_gt_wait_for_thread_c0(dev_priv);
 }
 
 static void __vlv_force_wake_put(struct drm_i915_private *dev_priv,