PCI: rcar: Save MSI controller in pci_sys_data

Save MSI controller in pci_sys_data instead of assigning MSI controller
pointer to every PCI bus in .add_bus().

[bhelgaas: use struct rcar_msi.chip, not ctrl]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/host/pcie-rcar.c

@@ -380,20 +380,10 @@ static int rcar_pcie_setup(int nr, struct pci_sys_data *sys)
 	return 1;
 }
 
-static void rcar_pcie_add_bus(struct pci_bus *bus)
-{
-	if (IS_ENABLED(CONFIG_PCI_MSI)) {
-		struct rcar_pcie *pcie = sys_to_pcie(bus->sysdata);
-
-		bus->msi = &pcie->msi.chip;
-	}
-}
-
 struct hw_pci rcar_pci = {
 	.setup          = rcar_pcie_setup,
 	.map_irq        = of_irq_parse_and_map_pci,
 	.ops            = &rcar_pcie_ops,
-	.add_bus        = rcar_pcie_add_bus,
 };
 
 static void rcar_pcie_enable(struct rcar_pcie *pcie)
@@ -402,6 +392,9 @@ static void rcar_pcie_enable(struct rcar_pcie *pcie)
 
 	rcar_pci.nr_controllers = 1;
 	rcar_pci.private_data = (void **)&pcie;
+#ifdef CONFIG_PCI_MSI
+	rcar_pci.msi_ctrl = &pcie->msi.chip;
+#endif
 
 	pci_common_init_dev(&pdev->dev, &rcar_pci);
 #ifdef CONFIG_PCI_DOMAINS