[PATCH] ARM: 2818/1: BAST - Use platform device for SuperIO 16550s

Patch from Ben Dooks

Use platform device for the 16500 UARTs in the onboard
SuperIO controller.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>