[POWERPC] iommu_free_table doesn't need the device_node

It only needs the iommu_table address.  It also makes use of the node
name to print error messages.  So just pass it the things it needs.
This reduces the places that know about the pci_dn by one.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/iommu.h b/include/asm-powerpc/iommu.h
index 4a82fdc..7a3cef7 100644
--- a/include/asm-powerpc/iommu.h
+++ b/include/asm-powerpc/iommu.h
@@ -69,10 +69,9 @@
 };
 
 struct scatterlist;
-struct device_node;
 
 /* Frees table for an individual device node */
-extern void iommu_free_table(struct device_node *dn);
+extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);
 
 /* Initializes an iommu_table based in values set in the passed-in
  * structure