cpufreq: pmac32-cpufreq: Fix refcount leak bug

In pmac_cpufreq_init_MacRISC3(), we need to add corresponding
of_node_put() for the three node pointers whose refcount have
been incremented by of_find_node_by_name().
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/pmac32-cpufreq.c

@@ -470,6 +470,10 @@ static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 	if (slew_done_gpio_np)
 		slew_done_gpio = read_gpio(slew_done_gpio_np);
 
+	of_node_put(volt_gpio_np);
+	of_node_put(freq_gpio_np);
+	of_node_put(slew_done_gpio_np);
+
 	/* If we use the frequency GPIOs, calculate the min/max speeds based
 	 * on the bus frequencies
 	 */