ARM: PCI: footbridge: provide a 'no swizzle' function for CATS

CATS sets its swizzle function to zero, which at the moment means
that no swizzling is required.  Make this explicit for CATS.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-footbridge/cats-pci.c

@@ -16,6 +16,11 @@
 /* cats host-specific stuff */
 static int irqmap_cats[] __initdata = { IRQ_PCI, IRQ_IN0, IRQ_IN1, IRQ_IN3 };
 
+static u8 cats_no_swizzle(struct pci_dev *dev, u8 *pin)
+{
+	return 0;
+}
+
 static int __init cats_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 {
 	if (dev->irq >= 255)
@@ -39,7 +44,7 @@ static int __init cats_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
  * cards being used (ie, pci-pci bridge based cards)?
  */
 static struct hw_pci cats_pci __initdata = {
-	.swizzle		= NULL,
+	.swizzle		= cats_no_swizzle,
 	.map_irq		= cats_map_irq,
 	.nr_controllers		= 1,
 	.setup			= dc21285_setup,