drm/i915: Reduce PSR re-activation time for VLV/CHV.

With 'commit 30886c5a ("drm/i915: VLV/CHV PSR: Increase wait delay
 time before active PSR.")' we fixed a blank screen when first
activation was happening immediately after PSR being enabled.
There we gave more time for idleness by increasing the delay
between re-activating sequences.

However, commit "drm/i915: Delay first PSR activation."
delay the first activation in a better way keeping a good PSR
residency. So, we can now reduce the delay on re-enable.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_psr.c

@@ -729,7 +729,6 @@ void intel_psr_flush(struct drm_device *dev,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_crtc *crtc;
 	enum pipe pipe;
-	int delay_ms = HAS_DDI(dev) ? 100 : 500;
 
 	mutex_lock(&dev_priv->psr.lock);
 	if (!dev_priv->psr.enabled) {
@@ -766,7 +765,7 @@ void intel_psr_flush(struct drm_device *dev,
 	if (!dev_priv->psr.active && !dev_priv->psr.busy_frontbuffer_bits)
 		if (!work_busy(&dev_priv->psr.work.work))
 			schedule_delayed_work(&dev_priv->psr.work,
-					      msecs_to_jiffies(delay_ms));
+					      msecs_to_jiffies(100));
 	mutex_unlock(&dev_priv->psr.lock);
 }