ARM: dts: Add CPU cooling binding for exynos3250 boards

This patch add the cooling device to control the overheating issue on
Exynos3250-based Rinato/Monk board.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>
diff --git a/arch/arm/boot/dts/exynos3250-monk.dts b/arch/arm/boot/dts/exynos3250-monk.dts
index 7863265..540a0ad 100644
--- a/arch/arm/boot/dts/exynos3250-monk.dts
+++ b/arch/arm/boot/dts/exynos3250-monk.dts
@@ -116,6 +116,21 @@
 		min-microvolt = <1100000>;
 		max-microvolt = <2700000>;
 	};
+
+	thermal-zones {
+		cpu_thermal: cpu-thermal {
+			cooling-maps {
+				map0 {
+					/* Correspond to 500MHz at freq_table */
+					cooling-device = <&cpu0 5 5>;
+				};
+				map1 {
+					/* Correspond to 200MHz at freq_table */
+					cooling-device = <&cpu0 8 8>;
+				};
+			};
+		};
+	};
 };
 
 &adc {