sparc: Machine description indices can vary

VIO devices were being looked up by their index in the machine
description node block, but this often varies over time as devices are
added and removed. Instead, store the ID and look up using the type,
config handle and ID.

Signed-off-by: James Clarke <jrtc27@jrtc27.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=112541
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/vio.h

@@ -327,6 +327,7 @@ struct vio_dev {
 	int			compat_len;
 
 	u64			dev_no;
+	u64			id;
 
 	unsigned long		channel_id;