cpufreq: exynos: Show a list of available frequencies

This patch adds freq_attr to show a list of exynos5440 scaling
available frequencies through sysfs. Common exynos driver already
supports this attribute.
Signed-off-by: NJungseok Lee <jays.lee@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/exynos5440-cpufreq.c

@@ -330,6 +330,7 @@ static struct cpufreq_driver exynos_driver = {
 	.init		= exynos_cpufreq_cpu_init,
 	.exit		= cpufreq_generic_exit,
 	.name		= CPUFREQ_NAME,
+	.attr		= cpufreq_generic_attr,
 };
 
 static const struct of_device_id exynos_cpufreq_match[] = {