drm/i915/ns2501: kill pll A enabling hack

With the pipe A quirk properly fixed up for i830M, this shouldn't be
required any longer.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index dd760f4..a55f664 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1432,7 +1432,7 @@
  *
  * Unfortunately needed by dvo_ns2501 since the dvo depends on it running.
  */
-void intel_enable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
+static void intel_enable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
 {
 	int reg;
 	u32 val;