powerpc/4xx: Allow 4xx PCI bridge to be disabled via device tree

This patch allows the 4xx (conventional) PCI bridge to be disabled
via the device tree. This is needed for 4xx PCI adapter hardware.

Use the PCI node's status property to disable the PCI bridge.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
Acked-by: Stefan Roese <sr@denx.de>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

arch/powerpc/sysdev/ppc4xx_pci.c

@@ -276,9 +276,16 @@ static void __init ppc4xx_probe_pci_bridge(struct device_node *np)
 	const int *bus_range;
 	int primary = 0;
 
+	/* Check if device is enabled */
+	if (!of_device_is_available(np)) {
+		printk(KERN_INFO "%s: Port disabled via device-tree\n",
+		       np->full_name);
+		return;
+	}
+
 	/* Fetch config space registers address */
 	if (of_address_to_resource(np, 0, &rsrc_cfg)) {
-		printk(KERN_ERR "%s:Can't get PCI config register base !",
+		printk(KERN_ERR "%s: Can't get PCI config register base !",
 		       np->full_name);
 		return;
 	}