PM / devfreq: tegra30: Constify structs

Constify unmodifiable structs, for consistency.
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Tested-by: NPeter Geis <pgwipeout@gmail.com>
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/tegra30-devfreq.c

@@ -108,7 +108,7 @@ enum tegra_actmon_device {
 	MCCPU,
 };
 
-static struct tegra_devfreq_device_config actmon_device_configs[] = {
+static const struct tegra_devfreq_device_config actmon_device_configs[] = {
 	{
 		/* MCALL: All memory accesses (including from the CPUs) */
 		.offset = 0x1c0,
@@ -177,7 +177,7 @@ struct tegra_actmon_emc_ratio {
 	unsigned long emc_freq;
 };
 
-static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
+static const struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
 	{ 1400000,    KHZ_MAX },
 	{ 1200000,    750000 },
 	{ 1100000,    600000 },
@@ -295,7 +295,7 @@ static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
 					    unsigned long cpu_freq)
 {
 	unsigned int i;
-	struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
+	const struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
 
 	for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {
 		if (cpu_freq >= ratio->cpu_freq) {