net: sfp: constify sfp-bus internal fwnode uses

Constify sfp-bus internal fwnode uses, since we do not modify the
fwnode structures.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/sfp-bus.c

@@ -17,7 +17,7 @@ struct sfp_bus {
 	/* private: */
 	struct kref kref;
 	struct list_head node;
-	struct fwnode_handle *fwnode;
+	const struct fwnode_handle *fwnode;
 
 	const struct sfp_socket_ops *socket_ops;
 	struct device *sfp_dev;
@@ -390,7 +390,7 @@ static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
 	return bus->registered ? bus->upstream_ops : NULL;
 }
 
-static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
+static struct sfp_bus *sfp_bus_get(const struct fwnode_handle *fwnode)
 {
 	struct sfp_bus *sfp, *new, *found = NULL;