xen: add backend driver support

Impact: backend device support

Add the basic machinery to support backend drivers.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
[corresponds to 79727b851bac in git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 43e2d7d..7a1d15f 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -94,7 +94,7 @@
 	int (*remove)(struct xenbus_device *dev);
 	int (*suspend)(struct xenbus_device *dev, pm_message_t state);
 	int (*resume)(struct xenbus_device *dev);
-	int (*uevent)(struct xenbus_device *, char **, int, char *, int);
+	int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
 	struct device_driver driver;
 	int (*read_otherend_details)(struct xenbus_device *dev);
 	int (*is_ready)(struct xenbus_device *dev);