powerpc/vio: Separate vio bus probe and device probe

Similar to PCI, separate the bus probe from device probe. This allows
us to attach bus notifiers for DMA debug and IOMMU fault injection
before devices have been probed.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/vio.c

@@ -1497,12 +1497,18 @@ static int __init vio_bus_init(void)
 	if (firmware_has_feature(FW_FEATURE_CMO))
 		vio_cmo_bus_init();
 
+	return 0;
+}
+postcore_initcall(vio_bus_init);
+
+static int __init vio_device_init(void)
+{
 	vio_bus_scan_register_devices("vdevice");
 	vio_bus_scan_register_devices("ibm,platform-facilities");
 
 	return 0;
 }
-__initcall(vio_bus_init);
+device_initcall(vio_device_init);
 
 static ssize_t name_show(struct device *dev,
 		struct device_attribute *attr, char *buf)