ARM: tegra: nexus7: Enable memory frequency thermal throttling using ACTMON

The ACTMON module monitors activity of memory clients and then devfreq
driver makes decisions about a required memory frequency based on info
from ACTMON. Add ACTMON device to the thermal zone of Nexus 7 in order
to use it as a cooling device which throttles memory freq on overheat.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra30-asus-nexus7-grouper-common.dtsi

@@ -1279,7 +1279,9 @@ map0 {
 					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 							 <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 							 <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&actmon THERMAL_NO_LIMIT
+								  THERMAL_NO_LIMIT>;
 				};
 			};
 		};