[POWERPC] pci_controller->arch_data really is a struct device_node *

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/pseries/iommu.c

@@ -251,7 +251,7 @@ static void iommu_table_setparms(struct pci_controller *phb,
 	const unsigned long *basep;
 	const u32 *sizep;
 
-	node = (struct device_node *)phb->arch_data;
+	node = phb->dn;
 
 	basep = of_get_property(node, "linux,tce-base", NULL);
 	sizep = of_get_property(node, "linux,tce-size", NULL);