PCI: mvebu: Check valid base address before port setup

This driver does not fail to probe when it cannot obtain
a port base address. Therefore, add a check for NULL base address
before setting up the port, which prevents a kernel panic in such
cases.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

drivers/pci/host/pci-mvebu.c

@@ -662,6 +662,8 @@ static int __init mvebu_pcie_setup(int nr, struct pci_sys_data *sys)
 
 	for (i = 0; i < pcie->nports; i++) {
 		struct mvebu_pcie_port *port = &pcie->ports[i];
+		if (!port->base)
+			continue;
 		mvebu_pcie_setup_hw(port);
 	}