drm/i915: Remove save/restore of physical HWS_PGA register

Now that we always restore the HWS registers (both physical and GTT
virtual addresses) when re-initialising the rings, we can eliminate the
superfluous save/restore of the register across suspend and resume.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -402,7 +402,6 @@ struct i915_suspend_saved_registers {
 	u32 saveDSPACNTR;
 	u32 saveDSPBCNTR;
 	u32 saveDSPARB;
-	u32 saveHWS;
 	u32 savePIPEACONF;
 	u32 savePIPEBCONF;
 	u32 savePIPEASRC;

drivers/gpu/drm/i915/i915_suspend.c

@@ -811,10 +811,6 @@ int i915_save_state(struct drm_device *dev)
 
 	mutex_lock(&dev->struct_mutex);
 
-	/* Hardware status page */
-	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		dev_priv->regfile.saveHWS = I915_READ(HWS_PGA);
-
 	i915_save_display(dev);
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET)) {
@@ -865,10 +861,6 @@ int i915_restore_state(struct drm_device *dev)
 
 	mutex_lock(&dev->struct_mutex);
 
-	/* Hardware status page */
-	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		I915_WRITE(HWS_PGA, dev_priv->regfile.saveHWS);
-
 	i915_restore_display(dev);
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET)) {