mvebu: 370 RD: Add support for the switch

The 370 rd has a 7 port, mv88E6182 switch, connected to eth1.  Add a
fixed-link subnode to the ethernet device tree node, to force
gigabit/full duplex.  Add a dsa node, with describing the four used
ports. This requires adding an alias to the mdio node, so it can be
referenced as a phandle.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1415214121-29286-3-git-send-email-andrew@lunn.ch


Signed-off-by: Jason Cooper <jason@lakedaemon.net>