Add class_data field to struct device, for the class drivers to use.

include/linux/device.h

@@ -65,7 +65,7 @@ struct bus_type {
 	struct driver_dir_entry	device_dir;
 	struct driver_dir_entry	driver_dir;
 
-	int	(*match)	(struct device * dev, struct device_driver * drv);
+	int		(*match)(struct device * dev, struct device_driver * drv);
 };
 
 
@@ -281,6 +281,8 @@ struct device {
 	void		*driver_data;	/* data private to the driver */
 
 	u32		class_num;	/* class-enumerated value */
+	void		* class_data;	/* class-specific data */
+
 	void		*platform_data;	/* Platform specific data (e.g. ACPI,
 					   BIOS data relevant to device) */