arm64: dts: allwinner: h6: Add cooling map for GPU

Add a simple cooling map for the GPU.

This cooling map come from the vendor kernel 4.9 with a
2°C hysteresis added.
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220906153034.153321-3-peron.clem@gmail.com

arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi

@@ -186,6 +186,7 @@ gpu: gpu@1800000 {
 			clocks = <&ccu CLK_GPU>, <&ccu CLK_BUS_GPU>;
 			clock-names = "core", "bus";
 			resets = <&ccu RST_BUS_GPU>;
+			#cooling-cells = <2>;
 			status = "disabled";
 		};
 
@@ -1072,9 +1073,55 @@ map0 {
 		};
 
 		gpu-thermal {
-			polling-delay-passive = <0>;
-			polling-delay = <0>;
+			polling-delay-passive = <1000>;
+			polling-delay = <2000>;
 			thermal-sensors = <&ths 1>;
+
+			trips {
+				gpu_alert0: gpu-alert-0 {
+					temperature = <95000>;
+					hysteresis = <2000>;
+					type = "passive";
+				};
+
+				gpu_alert1: gpu-alert-1 {
+					temperature = <100000>;
+					hysteresis = <2000>;
+					type = "passive";
+				};
+
+				gpu_alert2: gpu-alert-2 {
+					temperature = <105000>;
+					hysteresis = <2000>;
+					type = "passive";
+				};
+
+				gpu-crit {
+					temperature = <115000>;
+					hysteresis = <0>;
+					type = "critical";
+				};
+			};
+
+			cooling-maps {
+				// Forbid the GPU to go over 756MHz
+				map0 {
+					trip = <&gpu_alert0>;
+					cooling-device = <&gpu 1 THERMAL_NO_LIMIT>;
+				};
+
+				// Forbid the GPU to go over 624MHz
+				map1 {
+					trip = <&gpu_alert1>;
+					cooling-device = <&gpu 2 THERMAL_NO_LIMIT>;
+				};
+
+				// Forbid the GPU to go over 576MHz
+				map2 {
+					trip = <&gpu_alert2>;
+					cooling-device = <&gpu 3 THERMAL_NO_LIMIT>;
+				};
+			};
 		};
 	};
 };