drm/i915: disable/re-enable PCI device around S4 freeze/thaw

We already disable everything during S4 freeze, except the PCI device
itself. There is no reason why we couldn't disable that too and doing
so allows us to unify these handlers in the next patch with the
corresponding S3 suspend/resume handlers.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -1019,12 +1019,11 @@ static int i915_pm_freeze_late(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct drm_device *drm_dev = pci_get_drvdata(pdev);
-	struct drm_i915_private *dev_priv = drm_dev->dev_private;
 
 	if (drm_dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 		return 0;
 
-	return intel_suspend_complete(dev_priv);
+	return i915_drm_suspend_late(drm_dev);
 }
 
 static int i915_pm_thaw_early(struct device *dev)
@@ -1035,7 +1034,7 @@ static int i915_pm_thaw_early(struct device *dev)
 	if (drm_dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 		return 0;
 
-	return i915_drm_thaw_early(drm_dev);
+	return i915_resume_early(drm_dev);
 }
 
 static int i915_pm_thaw(struct device *dev)