powerpc/vio: Use device_type to detect family

Currently in the vio.c code we use a comparision against the parent
device node's full path to decide if the device is a PFO or VIO family
device.

Both the ibm,platform-facilities and vdevice nodes are defined by PAPR,
and must have a matching device_type. So instead of using the path we
can instead compare the device_type.

I've checked Qemu and kvmtool both do this correctly, and all the
PowerVM systems I have access to do also. So it seems to be safe.

This removes the dependency on full_name, which is being removed
upstream.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/pseries/vio.c

@@ -1357,9 +1357,9 @@ struct vio_dev *vio_register_device_node(struct device_node *of_node)
 	 */
 	parent_node = of_get_parent(of_node);
 	if (parent_node) {
-		if (!strcmp(parent_node->full_name, "/ibm,platform-facilities"))
+		if (!strcmp(parent_node->type, "ibm,platform-facilities"))
 			family = PFO;
-		else if (!strcmp(parent_node->full_name, "/vdevice"))
+		else if (!strcmp(parent_node->type, "vdevice"))
 			family = VDEVICE;
 		else {
 			pr_warn("%s: parent(%s) of %s not recognized.\n",