cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem

This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 06ce268..59f4261 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -291,10 +291,10 @@
 static int __cpuidle_register_device(struct cpuidle_device *dev)
 {
 	int ret;
-	struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
+	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
 
-	if (!sys_dev)
+	if (!dev)
 		return -EINVAL;
 	if (!try_module_get(cpuidle_driver->owner))
 		return -EINVAL;
@@ -303,7 +303,7 @@
 
 	per_cpu(cpuidle_devices, dev->cpu) = dev;
 	list_add(&dev->device_list, &cpuidle_detected_devices);
-	if ((ret = cpuidle_add_sysfs(sys_dev))) {
+	if ((ret = cpuidle_add_sysfs(cpu_dev))) {
 		module_put(cpuidle_driver->owner);
 		return ret;
 	}
@@ -344,7 +344,7 @@
  */
 void cpuidle_unregister_device(struct cpuidle_device *dev)
 {
-	struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
+	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
 
 	if (dev->registered == 0)
@@ -354,7 +354,7 @@
 
 	cpuidle_disable_device(dev);
 
-	cpuidle_remove_sysfs(sys_dev);
+	cpuidle_remove_sysfs(cpu_dev);
 	list_del(&dev->device_list);
 	wait_for_completion(&dev->kobj_unregister);
 	per_cpu(cpuidle_devices, dev->cpu) = NULL;
@@ -411,7 +411,7 @@
 	if (cpuidle_disabled())
 		return -ENODEV;
 
-	ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
+	ret = cpuidle_add_interface(cpu_subsys.dev_root);
 	if (ret)
 		return ret;