[cpu] Use sysdev.h instead of device.h and export cpu_sysdev_class

include/linux/cpu.h

@@ -19,7 +19,7 @@
 #ifndef _LINUX_CPU_H_
 #define _LINUX_CPU_H_
 
-#include <linux/device.h>
+#include <linux/sysdev.h>
 #include <linux/node.h>
 #include <asm/semaphore.h>
 
@@ -29,7 +29,7 @@ struct cpu {
 };
 
 extern int register_cpu(struct cpu *, int, struct node *);
-extern struct class cpu_class;
+extern struct sysdev_class cpu_sysdev_class;
 
 /* Stop CPUs going up and down. */
 extern struct semaphore cpucontrol;