ARM: Kirkwood: new board USI Topkick

This is a new kirkwood box made by Universal Scientific Industrial, Inc.
The product description is here:

http://www.usish.com/english/products_topkick1281p2.php

It is very similar to the dreamplug and other plug devices, with the
exception that it has room for a 2.5" SATA HDD internally.

Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>