PM / devfreq: tegra30: Support thermal cooling

Expose ACTMON devfreq device as a cooling device in order to throttle
memory freq on overheat. Throttling of memory freq has a significant
cooling effect on NVIDIA Tegra SoCs since higher memory freqs require
higher SoC core voltage which is one of the main causes of the heating.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/tegra30-devfreq.c

@@ -688,6 +688,7 @@ static struct devfreq_dev_profile tegra_devfreq_profile = {
 	.polling_ms	= ACTMON_SAMPLING_PERIOD,
 	.target		= tegra_devfreq_target,
 	.get_dev_status	= tegra_devfreq_get_dev_status,
+	.is_cooling_device = true,
 };
 
 static int tegra_governor_get_target(struct devfreq *devfreq,