xen/x86: Convert to hotplug state machine

Switch to new CPU hotplug infrastructure.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2 files changed