compositor: Pass both surface and seat in activation signal

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
diff --git a/libweston/compositor.h b/libweston/compositor.h
index 9219567..4177756 100644
--- a/libweston/compositor.h
+++ b/libweston/compositor.h
@@ -1011,6 +1011,11 @@
 	struct weston_buffer_viewport buffer_viewport;
 };
 
+struct weston_surface_activation_data {
+	struct weston_surface *surface;
+	struct weston_seat *seat;
+};
+
 struct weston_surface {
 	struct wl_resource *resource;
 	struct wl_signal destroy_signal; /* callback argument: this surface */