m68knommu: fix gpio warnings for ColdFire 527x targets

Fix these compiler warnings:

arch/m68knommu/platform/527x/gpio.c:37:3: warning: initialisation makes pointer from integer without a cast
arch/m68knommu/platform/527x/gpio.c:38:3: warning: initialisation makes pointer from integer without a cast
arch/m68knommu/platform/527x/gpio.c:39:3: warning: initialisation makes pointer from integer without a cast
arch/m68knommu/platform/527x/gpio.c:53:3: warning: initialisation makes pointer from integer without a cast
arch/m68knommu/platform/527x/gpio.c:54:3: warning: initialisation makes pointer from integer without a cast
arch/m68knommu/platform/527x/gpio.c:55:3: warning: initialisation makes pointer from integer without a cast
...
Signed-off-by: Greg Ungerer <gerg@uclinux.org>