arm64: dts: rockchip: rk3308: Add support to get cpu leakage

Change-Id: I55252c38a349b63bcc893dc913cb43c445bf8c94
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>

Author: finley1226

arch/arm64/boot/dts/rockchip/rk3308.dtsi

@@ -98,6 +98,9 @@
 		compatible = "operating-points-v2";
 		opp-shared;
 
+		nvmem-cells = <&cpu_leakage>;
+		nvmem-cell-names = "leakage";
+
 		opp-408000000 {
 			opp-hz = /bits/ 64 <408000000>;
 			opp-microvolt = <950000 950000 1340000>;