PCI: Move out pci_enable_bridges out of assign_unsigned_bus_res

So could use assign_unassigned_bus_res pci root bus add

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 65f62e3..59cf1ba 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1905,6 +1905,7 @@
 
 	max = pci_scan_child_bus(bus);
 	pci_assign_unassigned_bus_resources(bus);
+	pci_enable_bridges(bus);
 	pci_bus_add_devices(bus);
 
 	return max;