powerpc: eliminate DsaAddr from pci_dn

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/arch/powerpc/platforms/iseries/iommu.c b/arch/powerpc/platforms/iseries/iommu.c
index 533d9b4..1db26d8 100644
--- a/arch/powerpc/platforms/iseries/iommu.c
+++ b/arch/powerpc/platforms/iseries/iommu.c
@@ -124,7 +124,7 @@
 
 	memset(parms, 0, sizeof(*parms));
 
-	parms->itc_busno = pdn->DsaAddr.Dsa.busNumber;
+	parms->itc_busno = pdn->busno;
 	parms->itc_slotno = pdn->LogicalSlot;
 	parms->itc_virtbus = 0;