drm/i915: make backlight info per-connector

Move from dev_priv to connector->panel. We still don't allow multiple
sysfs interfaces, though.

There should be no functional changes, except for a slight reordering of
connector backlight and sysfs destroy calls. (This change happens now
that the backlight device is actually per-connector, even though the
destroy calls became per-connector earlier.)

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5548180..9460e54 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -156,6 +156,13 @@
 struct intel_panel {
 	struct drm_display_mode *fixed_mode;
 	int fitting_mode;
+
+	/* backlight */
+	struct {
+		u32 level;
+		bool enabled;
+		struct backlight_device *device;
+	} backlight;
 };
 
 struct intel_connector {