i915: do not setup intel_backlight twice

The commit "Not all systems expose a firmware or platform mechanism for
changing the backlight intensity on i915, so add native driver support"
adds calls to  intel_panel_setup_backlight() from intel_{lvds,dp}_init
so do not call it again from intel_setup_outputs().

BugLink: http://bugs.launchpad.net/bugs/831542

Signed-off-by: Kamal Mostafa <kamal@canonical.com>
ACKed-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

drivers/gpu/drm/i915/intel_display.c

@@ -7238,8 +7238,6 @@ static void intel_setup_outputs(struct drm_device *dev)
 			intel_encoder_clones(dev, encoder->clone_mask);
 	}
 
-	intel_panel_setup_backlight(dev);
-
 	/* disable all the possible outputs/crtcs before entering KMS mode */
 	drm_helper_disable_unused_functions(dev);
 }