drivers: make device_type const

The device_type structure does not contain data that changes
during usage and should be const. This allows devices to declare
the struct const.

I have patches to change all the subsystems, but need the infra
structure change first.

Signed-off-by: Stephen Hemminger <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/base/core.c

···
 static int device_add_attrs(struct device *dev)
 {
 	struct class *class = dev->class;
-	struct device_type *type = dev->type;
+	const struct device_type *type = dev->type;
 	int error;
 
 	if (class) {
···
 static void device_remove_attrs(struct device *dev)
 {
 	struct class *class = dev->class;
-	struct device_type *type = dev->type;
+	const struct device_type *type = dev->type;
 
 	device_remove_groups(dev, dev->groups);
 

include/linux/device.h

···
 
 	struct kobject kobj;
 	const char		*init_name; /* initial name of the device */
-	struct device_type	*type;
+	const struct device_type *type;
 
 	struct mutex		mutex;	/* mutex to synchronize calls to
 					 * its driver.