drm/i915: Hide gen6_update_ring_freq()

This function is no longer used outside of intel_pm.c so we can stop
exposing it and rename the __gen6_update_ring_freq() to take its place.

Suggested-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1468397438-21226-8-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index c77ec10..fa6b341 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5436,7 +5436,7 @@
 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
 }
 
-static void __gen6_update_ring_freq(struct drm_i915_private *dev_priv)
+static void gen6_update_ring_freq(struct drm_i915_private *dev_priv)
 {
 	int min_freq = 15;
 	unsigned int gpu_freq;
@@ -5520,16 +5520,6 @@
 	}
 }
 
-void gen6_update_ring_freq(struct drm_i915_private *dev_priv)
-{
-	if (!HAS_CORE_RING_FREQ(dev_priv))
-		return;
-
-	mutex_lock(&dev_priv->rps.hw_lock);
-	__gen6_update_ring_freq(dev_priv);
-	mutex_unlock(&dev_priv->rps.hw_lock);
-}
-
 static int cherryview_rps_max_freq(struct drm_i915_private *dev_priv)
 {
 	u32 val, rp0;
@@ -6624,13 +6614,13 @@
 		gen9_enable_rc6(dev_priv);
 		gen9_enable_rps(dev_priv);
 		if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv))
-			__gen6_update_ring_freq(dev_priv);
+			gen6_update_ring_freq(dev_priv);
 	} else if (IS_BROADWELL(dev_priv)) {
 		gen8_enable_rps(dev_priv);
-		__gen6_update_ring_freq(dev_priv);
+		gen6_update_ring_freq(dev_priv);
 	} else if (INTEL_GEN(dev_priv) >= 6) {
 		gen6_enable_rps(dev_priv);
-		__gen6_update_ring_freq(dev_priv);
+		gen6_update_ring_freq(dev_priv);
 	} else if (IS_IRONLAKE_M(dev_priv)) {
 		ironlake_enable_drps(dev_priv);
 		intel_init_emon(dev_priv);