ARM: sunxi: fix a leaked reference by adding missing of_node_put

The call to of_get_next_child returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
./arch/arm/mach-sunxi/platsmp.c:55:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 46, but without a corresponding object release within this function.
./arch/arm/mach-sunxi/platsmp.c:138:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 129, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

arch/arm/mach-sunxi/platsmp.c

@@ -50,6 +50,7 @@ static void __init sun6i_smp_prepare_cpus(unsigned int max_cpus)
 	}
 
 	prcm_membase = of_iomap(node, 0);
+	of_node_put(node);
 	if (!prcm_membase) {
 		pr_err("Couldn't map A31 PRCM registers\n");
 		return;
@@ -63,6 +64,7 @@ static void __init sun6i_smp_prepare_cpus(unsigned int max_cpus)
 	}
 
 	cpucfg_membase = of_iomap(node, 0);
+	of_node_put(node);
 	if (!cpucfg_membase)
 		pr_err("Couldn't map A31 CPU config registers\n");