drm/i915: GEN6_RP_INTERRUPT_LIMITS doesn't seem to exist on VLV

I can't find GEN6_RP_INTERRUPT_LIMITS (0xA014) anywhere in VLV docs.
Reading it always returns zero from what I can tell, and eliminating
it doesn't seem to make any difference to the behaviour of the system.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -3104,7 +3104,8 @@ static void vlv_update_rps_cur_delay(struct drm_i915_private *dev_priv)
 void valleyview_set_rps(struct drm_device *dev, u8 val)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 limits = gen6_rps_limits(dev_priv, &val);
+
+	gen6_rps_limits(dev_priv, &val);
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 	WARN_ON(val > dev_priv->rps.max_delay);
@@ -3123,11 +3124,6 @@ void valleyview_set_rps(struct drm_device *dev, u8 val)
 
 	vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ, val);
 
-	/* Make sure we continue to get interrupts
-	 * until we hit the minimum or maximum frequencies.
-	 */
-	I915_WRITE(GEN6_RP_INTERRUPT_LIMITS, limits);
-
 	dev_priv->rps.cur_delay = val;
 
 	trace_intel_gpu_freq_change(vlv_gpu_freq(dev_priv->mem_freq, val));