drm/i915: s/intel_encoder_disable/intel_encoder_noop

Because that's what it is. Unfortunately we can't rip this out because
the fb helper has an incetious relationship with the crtc helper - it
likes to call disable_unused_functions, among other things.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
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 b843bc0..9a06611 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3553,7 +3553,7 @@
 	}
 }
 
-void intel_encoder_disable(struct drm_encoder *encoder)
+void intel_encoder_noop(struct drm_encoder *encoder)
 {
 }