acpi: mark PMTIMER as unlocked

Accessing QEMU_CLOCK_VIRTUAL is thread-safe.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <1434646046-27150-9-git-send-email-pbonzini@redhat.com>

hw/acpi/core.c

@@ -528,6 +528,7 @@ void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci,
     ar->tmr.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, acpi_pm_tmr_timer, ar);
     memory_region_init_io(&ar->tmr.io, memory_region_owner(parent),
                           &acpi_pm_tmr_ops, ar, "acpi-tmr", 4);
+    memory_region_clear_global_locking(&ar->tmr.io);
     memory_region_add_subregion(parent, 8, &ar->tmr.io);
 }