[ARM] 3037/1: AAED-2000 - Add defines for GPIO registers on external port.

Patch from Bellido Nicolas

The AAED-2000 board has GPIO pins on an external port.
This patch adds the defines, and do the necessary mapping.

Signed-off-by: Nicolas Bellido <ml@acolin.be>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>