w1: core: match sub-nodes of bus masters in devicetree

Once a new slave device is detected, match it against all sub-nodes of the
master bus controller. If a match is found, set the slave device's of_node
pointer.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

include/linux/w1.h

@@ -274,6 +274,8 @@ struct w1_family {
 
 	struct w1_family_ops	*fops;
 
+	const struct of_device_id *of_match_table;
+
 	atomic_t		refcnt;
 };