cpuidle-haltpoll: disable host side polling when kvm virtualized

When performing guest side polling, it is not necessary to
also perform host side polling.

So disable host side polling, via the new MSR interface,
when loading cpuidle-haltpoll driver.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>