[POWERPC] 83xx: Add support for Analogue & Micro ASP837E board

The following adds support for the Analogue & Micro ASP 8347E, running
Redboot.

http://www.analogue-micro.com/ASP8347.html



Signed-off-by: Bryan O'Donoghue <bodonoghue@codehermit.ie>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>