drm/i915: Don't save/restore hardware status page address register

It's cleaned before saving and re-initialized after restoring.
So don't need to save/restore it. And also new chip has new address
for hardware status page register, don't write to old address.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_drv.h

@@ -383,7 +383,6 @@ typedef struct drm_i915_private {
 	u32 saveDSPACNTR;
 	u32 saveDSPBCNTR;
 	u32 saveDSPARB;
-	u32 saveHWS;
 	u32 savePIPEACONF;
 	u32 savePIPEBCONF;
 	u32 savePIPEASRC;

drivers/gpu/drm/i915/i915_suspend.c

@@ -796,9 +796,6 @@ int i915_save_state(struct drm_device *dev)
 
 	pci_read_config_byte(dev->pdev, LBB, &dev_priv->saveLBB);
 
-	/* Hardware status page */
-	dev_priv->saveHWS = I915_READ(HWS_PGA);
-
 	i915_save_display(dev);
 
 	/* Interrupt state */
@@ -845,9 +842,6 @@ int i915_restore_state(struct drm_device *dev)
 
 	pci_write_config_byte(dev->pdev, LBB, dev_priv->saveLBB);
 
-	/* Hardware status page */
-	I915_WRITE(HWS_PGA, dev_priv->saveHWS);
-
 	i915_restore_display(dev);
 
 	/* Interrupt state */