PCI: xgene: Use pci_host_probe() to register host

The xgene host driver does the same host registration and bus scanning
calls as pci_host_probe, so let's use it instead.

Link: https://lore.kernel.org/r/20200522234832.954484-10-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Toan Le <toan@os.amperecomputing.com>

drivers/pci/controller/pci-xgene.c

@@ -591,7 +591,6 @@ static int xgene_pcie_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *dn = dev->of_node;
 	struct xgene_pcie_port *port;
-	struct pci_bus *bus, *child;
 	struct pci_host_bridge *bridge;
 	int ret;
 
@@ -632,17 +631,7 @@ static int xgene_pcie_probe(struct platform_device *pdev)
 	bridge->map_irq = of_irq_parse_and_map_pci;
 	bridge->swizzle_irq = pci_common_swizzle;
 
-	ret = pci_scan_root_bus_bridge(bridge);
-	if (ret < 0)
-		return ret;
-
-	bus = bridge->bus;
-
-	pci_assign_unassigned_bus_resources(bus);
-	list_for_each_entry(child, &bus->children, node)
-		pcie_bus_configure_settings(child);
-	pci_bus_add_devices(bus);
-	return 0;
+	return pci_host_probe(bridge);
 }
 
 static const struct of_device_id xgene_pcie_match_table[] = {