[ARM] Kirkwood: Add support for HP t5325 Thin Client

Add support for the HP t5325 Thin Client.  This thin client is based
on a Marvell Kirkwood chip at 1.2 GHz and features 512 MB RAM, 512 MB
SATA-attached flash and an XGI Volari Z11 GPU.

Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>