[ARM] ixp4xx: fix IRQ GPIO direction configuration for GPIOs >= 8

I believe that the following patch is necessary to properly configure
GPIO line configuration for IRQ's which are mapped to a GPIO line >= 8
(without this patch the wrong GPIO is configured as an input.)

Signed-off-by: Tim Harvey <tim_harvey@yahoo.com>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>