clk: imx31: add missing of_node_put

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

The semantic patch that fixes this problem is as follows
(http://coccinelle.lip6.fr

):

// <smpl>
@@
local idexpression n;
expression e;
@@

 for_each_compatible_node(n,...) {
   ...
(
   of_node_put(n);
|
   e = n
|
+  of_node_put(n);
?  break;
)
   ...
 }
... when != n
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>