cpufreq: powernv: Free 'chips' on module exit

BugLink: http://bugs.launchpad.net/bugs/1555765

This will free the dynamically allocated memory of 'chips' on
module exit.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from linux-next commit 86622cb8)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/cpufreq/powernv-cpufreq.c

@@ -612,6 +612,7 @@ static void __exit powernv_cpufreq_exit(void)
 	unregister_reboot_notifier(&powernv_cpufreq_reboot_nb);
 	opal_message_notifier_unregister(OPAL_MSG_OCC,
 					 &powernv_cpufreq_opal_nb);
+	kfree(chips);
 	cpufreq_unregister_driver(&powernv_cpufreq_driver);
 }
 module_exit(powernv_cpufreq_exit);