drm/i915: Silence valleyview_set_rps()

Even with the rps debug messages signficantly recuced  by
 commit 67956867aa07c59d6d83628bbc9ee4bd9799a1e1
 Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
 Date:   Tue Sep 2 15:12:17 2014 +0300

    drm/i915: Don't spam dmesg with rps messages on vlv/chv

we still get an inordinate amount of spam from this. Just kill the debug
print. If someone wants to observe it they can just use the tracepoint.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4504,14 +4504,8 @@ void valleyview_set_rps(struct drm_device *dev, u8 val)
 		      "Odd GPU freq value\n"))
 		val &= ~1;
 
-	if (val != dev_priv->rps.cur_freq) {
-		DRM_DEBUG_DRIVER("GPU freq request from %d MHz (%u) to %d MHz (%u)\n",
-				 vlv_gpu_freq(dev_priv, dev_priv->rps.cur_freq),
-				 dev_priv->rps.cur_freq,
-				 vlv_gpu_freq(dev_priv, val), val);
-
+	if (val != dev_priv->rps.cur_freq)
 		vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ, val);
-	}
 
 	I915_WRITE(GEN6_PMINTRMSK, gen6_rps_pm_mask(dev_priv, val));