dm: pci: Pass only device/function to pci_bus_find_devfn()

In dm_pci_hose_probe_bus(), pci_bus_find_devfn() is called with a bdf
which includes a bus number, but it really should not as this routine
only expects a device/function encoding.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index 6d0696a..bc0be1e 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -326,7 +326,7 @@
 	parent = hose->bus;
 
 	/* Find the bus within the parent */
-	ret = pci_bus_find_devfn(parent, bdf, &bus);
+	ret = pci_bus_find_devfn(parent, PCI_MASK_BUS(bdf), &bus);
 	if (ret) {
 		debug("%s: Cannot find device %x on bus %s: %d\n", __func__,
 		      bdf, parent->name, ret);