PCI: xgene: Assign resources to bus before adding new devices

The X-Gene PCIe driver assumes pci_scan_root_bus() assigns resources as
proposed in [1].  But we dropped patch [1] because it would break some
architectures, which means the X-Gene PCIe driver is currently broken.

Add calls to scan the bus, assign resources, and add devices in the X-Gene
driver to fix this.

[bhelgaas: changelog]
[1] http://lkml.kernel.org/r/1412000971-9242-11-git-send-email-Liviu.Dudau@arm.com
Signed-off-by: Duc Dang <dhdang@apm.com>
Signed-off-by: Tanmay Inamdar <tinamdar@apm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/host/pci-xgene.c

@@ -631,10 +631,15 @@ static int xgene_pcie_probe_bridge(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	bus = pci_scan_root_bus(&pdev->dev, 0, &xgene_pcie_ops, port, &res);
+	bus = pci_create_root_bus(&pdev->dev, 0,
+					&xgene_pcie_ops, port, &res);
 	if (!bus)
 		return -ENOMEM;
 
+	pci_scan_child_bus(bus);
+	pci_assign_unassigned_bus_resources(bus);
+	pci_bus_add_devices(bus);
+
 	platform_set_drvdata(pdev, port);
 	return 0;
 }