pinctrl: sh-pfc: add missing of_node_put

for_each_child_of_node performs an of_node_get on each iteration, so a
goto out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr

):

// <smpl>
@@
local idexpression n;
expression e,e1;
identifier l;
@@

 for_each_child_of_node(e1,n) {
   ...
(
   of_node_put(n);
|
   e = n
|
   return n;
|
+  of_node_put(n);
?  goto l;
)
   ...
 }
l: ... when != n
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>