cpuidle-haltpoll: do not set an owner to allow modunload

cpuidle-haltpoll can be built as a module to allow optional late load.
Given we are setting @owner to THIS_MODULE, cpuidle will attempt to grab a
module reference every time a cpuidle_device is registered -- so
essentially all online cpus get a reference.

This prevents for the module to be unloaded later, which makes the
module_exit callback entirely unused. Thus remove the @owner and allow
module to be unloaded.

Fixes: fa86ee9 ("add cpuidle-haltpoll driver")
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/cpuidle-haltpoll.c

@@ -35,7 +35,6 @@ static int default_enter_idle(struct cpuidle_device *dev,
 static struct cpuidle_driver haltpoll_driver = {
 	.name = "haltpoll",
 	.governor = "haltpoll",
-	.owner = THIS_MODULE,
 	.states = {
 		{ /* entry 0 is for polling */ },
 		{