ARM: dts: rockchip: add cpu opp table for rv1108

Add cpu opp table for rv1108 to support frequency
from 408MHZ to 1008MHZ.
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rv1108.dtsi

@@ -69,6 +69,33 @@ cpu0: cpu@f00 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a7";
 			reg = <0xf00>;
+			clocks = <&cru ARMCLK>;
+			operating-points-v2 = <&cpu_opp_table>;
+		};
+	};
+
+	cpu_opp_table: opp_table {
+		compatible = "operating-points-v2";
+
+		opp-408000000 {
+			opp-hz = /bits/ 64 <408000000>;
+			opp-microvolt = <975000>;
+			clock-latency-ns = <40000>;
+		};
+		opp-600000000 {
+			opp-hz = /bits/ 64 <600000000>;
+			opp-microvolt = <975000>;
+			clock-latency-ns = <40000>;
+		};
+		opp-816000000 {
+			opp-hz = /bits/ 64 <816000000>;
+			opp-microvolt = <1025000>;
+			clock-latency-ns = <40000>;
+		};
+		opp-1008000000 {
+			opp-hz = /bits/ 64 <1008000000>;
+			opp-microvolt = <1150000>;
+			clock-latency-ns = <40000>;
 		};
 	};