rocker: introduce worlds infrastructure

This is another step on the way to per-world clean cut. Introduce world
ops hooks which each world can implement in world-specific way.
Also introduce world infrastructure along with OF-DPA world stub.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/rocker/rocker_ofdpa.c

@@ -0,0 +1,27 @@
+/*
+ * drivers/net/ethernet/rocker/rocker_ofdpa.c - Rocker switch OF-DPA-like
+ *					        implementation
+ * Copyright (c) 2014 Scott Feldman <sfeldma@gmail.com>
+ * Copyright (c) 2014-2016 Jiri Pirko <jiri@mellanox.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include "rocker.h"
+
+struct ofdpa {
+};
+
+struct ofdpa_port {
+};
+
+struct rocker_world_ops rocker_ofdpa_ops = {
+	.kind = "ofdpa",
+	.priv_size = sizeof(struct ofdpa),
+	.port_priv_size = sizeof(struct ofdpa_port),
+	.mode = ROCKER_PORT_MODE_OF_DPA,
+};