driver core: Introduce device_find_child().

Introduce device_find_child() to match device_for_each_child().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/device.h b/include/linux/device.h
index 2d9dc35..0a0370c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -421,6 +421,8 @@
 extern void device_del(struct device * dev);
 extern int device_for_each_child(struct device *, void *,
 		     int (*fn)(struct device *, void *));
+extern struct device *device_find_child(struct device *, void *data,
+					int (*match)(struct device *, void *));
 extern int device_rename(struct device *dev, char *new_name);
 
 /*