of: Clear detach flag on attach

When attaching a node always clear the detach flag. Without this change
the sequence detach, attach fails.

Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ff85450..87038d8 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1692,6 +1692,7 @@
 	np->allnext = of_allnodes;
 	np->parent->child = np;
 	of_allnodes = np;
+	of_node_clear_flag(np, OF_DETACHED);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
 	of_add_proc_dt_entry(np);