PCI: iproc: Convert PCI scan API to pci_scan_root_bus_bridge()

The introduction of pci_scan_root_bus_bridge() provides a PCI core API to
scan a PCI root bus backed by an already initialized struct pci_host_bridge
object, which simplifies the bus scan interface and makes the PCI scan root
bus interface easier to generalize as members are added to the struct
pci_host_bridge.

Convert PCI iproc host code to pci_scan_root_bus_bridge() to improve the
PCI root bus scanning interface.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Jon Mason <jonmason@broadcom.com>
diff --git a/drivers/pci/host/pcie-iproc-platform.c b/drivers/pci/host/pcie-iproc-platform.c
index 90d2bdd..2253119 100644
--- a/drivers/pci/host/pcie-iproc-platform.c
+++ b/drivers/pci/host/pcie-iproc-platform.c
@@ -52,12 +52,15 @@ static int iproc_pcie_pltfm_probe(struct platform_device *pdev)
 	struct resource reg;
 	resource_size_t iobase = 0;
 	LIST_HEAD(resources);
+	struct pci_host_bridge *bridge;
 	int ret;
 
-	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
-	if (!pcie)
+	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
+	if (!bridge)
 		return -ENOMEM;
 
+	pcie = pci_host_bridge_priv(bridge);
+
 	pcie->dev = dev;
 	pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev);