arm64: dts: rockchip: add rk3399 thermal_zones phandle

We're going to need to amend this table in board files.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399.dtsi

@@ -607,7 +607,7 @@ spi5: spi@ff200000 {
 		status = "disabled";
 	};
 
-	thermal-zones {
+	thermal_zones: thermal-zones {
 		cpu_thermal: cpu {
 			polling-delay-passive = <100>;
 			polling-delay = <1000>;