cpuidle-haltpoll: select haltpoll governor

The haltpoll cpuidle driver should select the haltpoll governor, so
as to ensure that they work together.
Signed-off-by: Li RongQing <lirongqing@baidu.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/Kconfig

@@ -74,6 +74,7 @@ endmenu
 config HALTPOLL_CPUIDLE
 	tristate "Halt poll cpuidle driver"
 	depends on X86 && KVM_GUEST
+	select CPU_IDLE_GOV_HALTPOLL
 	default y
 	help
 	 This option enables halt poll cpuidle driver, which allows to poll