drm/i915: Remove defunct intel_suspend_gt_powersave()

Since commit b7137e0c ("drm/i915: Defer enabling rc6 til after we
submit the first batch/context"), intel_suspend_gt_powersave() has been
a no-op. As we still do not need to do anything explicitly on suspend
(we do everything required on idling), remove the defunct function.

References: b7137e0c ("drm/i915: Defer enabling rc6 til after we submit the first batch/context")
Suggested-by: "Hiatt, Don" <don.hiatt@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190323214009.23294-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem.c

@@ -4397,7 +4397,6 @@ void i915_gem_suspend(struct drm_i915_private *i915)
 	GEM_TRACE("\n");
 
 	wakeref = intel_runtime_pm_get(i915);
-	intel_suspend_gt_powersave(i915);
 
 	flush_workqueue(i915->wq);
 

drivers/gpu/drm/i915/intel_drv.h

@@ -2374,7 +2374,6 @@ void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_enable_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_disable_gt_powersave(struct drm_i915_private *dev_priv);
-void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv);
 void gen6_rps_busy(struct drm_i915_private *dev_priv);
 void gen6_rps_reset_ei(struct drm_i915_private *dev_priv);
 void gen6_rps_idle(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_pm.c

@@ -8494,22 +8494,6 @@ void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
 		pm_runtime_put(&dev_priv->drm.pdev->dev);
 }
 
-/**
- * intel_suspend_gt_powersave - suspend PM work and helper threads
- * @dev_priv: i915 device
- *
- * We don't want to disable RC6 or other features here, we just want
- * to make sure any work we've queued has finished and won't bother
- * us while we're suspended.
- */
-void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv)
-{
-	if (INTEL_GEN(dev_priv) < 6)
-		return;
-
-	/* gen6_rps_idle() will be called later to disable interrupts */
-}
-
 void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv)
 {
 	dev_priv->gt_pm.rps.enabled = true; /* force RPS disabling */