ivi-shell: rework create_surface notification

The add_notification_create_surface API accepts a simple
wl_listener instead of a ivi-shell specific notification
function. Therefore, the API is renamed to
add_listener_create_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_create_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 d7a880c..2ea43bb 100644
--- a/ivi-shell/ivi-layout-export.h
+++ b/ivi-shell/ivi-layout-export.h
@@ -146,10 +146,6 @@
 			struct ivi_layout_layer *ivilayer,
 			void *userdata);
 
-typedef void (*surface_create_notification_func)(
-			struct ivi_layout_surface *ivisurf,
-			void *userdata);
-
 typedef void (*surface_remove_notification_func)(
 			struct ivi_layout_surface *ivisurf,
 			void *userdata);
@@ -174,15 +170,14 @@
 	 */
 
 	/**
-	 * \brief register/unregister for notification when ivi_surface is created
+	 * \brief add a listener for notification when ivi_surface is created
+	 *
+	 * When an ivi_surface is created, a signal is emitted
+	 * to the listening controller plugins.
+	 * The pointer of the created ivi_surface is sent as the void *data argument
+	 * to the wl_listener::notify callback function of the listener.
 	 */
-	int32_t (*add_notification_create_surface)(
-				surface_create_notification_func callback,
-				void *userdata);
-
-	void (*remove_notification_create_surface)(
-				surface_create_notification_func callback,
-				void *userdata);
+	int32_t (*add_listener_create_surface)(struct wl_listener *listener);
 
 	/**
 	 * \brief register/unregister for notification when ivi_surface is removed