compositor: Remove the edges parameter from send_configure

send_configure was originally modelled after
wl_shell_surface::send_configure, which takes these arguments. However,
the X WM and xdg_surface::configure variants don't use these arguments.

We already store the resize edges for a surface while it's being
resized, so just use the saved state in the wl_shell_surface variant.
diff --git a/src/compositor.h b/src/compositor.h
index 1997e54..057f8be 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -82,8 +82,7 @@
 };
 
 struct weston_shell_client {
-	void (*send_configure)(struct weston_surface *surface,
-			       uint32_t edges, int32_t width, int32_t height);
+	void (*send_configure)(struct weston_surface *surface, int32_t width, int32_t height);
 };
 
 struct weston_shell_interface {