drm/i915: make sure we shut off the panel in eDP configs

Fix error from the last pull request.  Making sure we shut the panel off
is more correct and saves power.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/i915/intel_dp.c

@@ -798,7 +798,7 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode)
 			intel_dp_link_down(intel_encoder, dp_priv->DP);
 			if (IS_eDP(intel_encoder)) {
 				ironlake_edp_backlight_off(dev);
-				ironlake_edp_backlight_off(dev);
+				ironlake_edp_panel_off(dev);
 			}
 		}
 	} else {