Revert "drm/i915: set conservative clock gating values on VLV v2"

We're disabling a boatload of clock gating features on VLV. Maybe these
days we don't need to do that. At least I'm not aware of any workarounds
with this level of paranoia.

This reverts commit 4e8c84a5b14bbb5b88c63941f1d939560f4abd0b.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4963,16 +4963,7 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
 	 * Disable clock gating on th GCFG unit to prevent a delay
 	 * in the reporting of vblank events.
 	 */
-	I915_WRITE(VLV_GUNIT_CLOCK_GATE, 0xffffffff);
-
-	/* Conservative clock gating settings for now */
-	I915_WRITE(0x9400, 0xffffffff);
-	I915_WRITE(0x9404, 0xffffffff);
-	I915_WRITE(0x9408, 0xffffffff);
-	I915_WRITE(0x940c, 0xffffffff);
-	I915_WRITE(0x9410, 0xffffffff);
-	I915_WRITE(0x9414, 0xffffffff);
-	I915_WRITE(0x9418, 0xffffffff);
+	I915_WRITE(VLV_GUNIT_CLOCK_GATE, GCFG_DIS);
 }
 
 static void g4x_init_clock_gating(struct drm_device *dev)