ivi-shell: rework remove_surface notification

The add_notification_remove_surface API accepts a simple
wl_listener instead of a ivi-shell specific notification
function. Therefore, the API is renamed to add_listener_remove_surface.

This change has several advantages:
1. Code cleanup
2. No dynamic memory allocation. Listeners are allocated
   by controller plugins
3. Remove API is not needed. Controller plugins can easily
   remove the listener link.

The remove API is removed too:
- ivi_layout_remove_notification_remove_surface

Signed-off-by: Emre Ucan <eucan@de.adit-jv.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/ivi-shell/ivi-layout-export.h b/ivi-shell/ivi-layout-export.h
index 2ed1e76..1485d3f 100644
--- a/ivi-shell/ivi-layout-export.h
+++ b/ivi-shell/ivi-layout-export.h
@@ -138,10 +138,6 @@
 	IVI_LAYOUT_TRANSITION_MAX,
 };
 
-typedef void (*surface_remove_notification_func)(
-			struct ivi_layout_surface *ivisurf,
-			void *userdata);
-
 typedef void (*surface_configure_notification_func)(
 			struct ivi_layout_surface *ivisurf,
 			void *userdata);
@@ -172,15 +168,14 @@
 	int32_t (*add_listener_create_surface)(struct wl_listener *listener);
 
 	/**
-	 * \brief register/unregister for notification when ivi_surface is removed
+	 * \brief add a listener for notification when ivi_surface is removed
+	 *
+	 * When an ivi_surface is removed, a signal is emitted
+	 * to the listening controller plugins.
+	 * The pointer of the removed ivi_surface is sent as the void *data argument
+	 * to the wl_listener::notify callback function of the listener.
 	 */
-	int32_t (*add_notification_remove_surface)(
-				surface_remove_notification_func callback,
-				void *userdata);
-
-	void (*remove_notification_remove_surface)(
-				surface_remove_notification_func callback,
-				void *userdata);
+	int32_t (*add_listener_remove_surface)(struct wl_listener *listener);
 
 	/**
 	 * \brief register/unregister for notification when ivi_surface is configured