ARM: imx: Add missing of_node_put()

After finishing using device node got from of_find_compatible_node(),
of_node_put() needs to be called.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/mach-imx/gpc.c

@@ -282,4 +282,5 @@ void __init imx_gpc_check_dt(void)
 		/* map GPC, so that at least CPUidle and WARs keep working */
 		gpc_base = of_iomap(np, 0);
 	}
+	of_node_put(np);
 }