[nrf fromlist] dts: arm: nordic: Define power states for nrf54h20/cpuapp

Add definition of low power states 'idle' and 's2ram'
for nrf54h20/cpuapp.

Upstream PR: zephyrproject-rtos/zephyr#79098

Signed-off-by: Sebastian Głąb <[email protected]>

Author: nordic-segl

dts/arm/nordic/nrf54h20_cpuapp.dtsi

@@ -57,3 +57,23 @@ wdt011: &cpuapp_wdt011 {};
 &grtc {
 	interrupts = <109 NRF_DEFAULT_IRQ_PRIORITY>;
 };
+
+&cpus {
+	power-states {
+		idle: idle {
+			compatible = "zephyr,power-state";
+			power-state-name = "suspend-to-idle";
+			min-residency-us = <100000>;
+		};
+
+		s2ram: s2ram {
+			compatible = "zephyr,power-state";
+			power-state-name = "suspend-to-ram";
+			min-residency-us = <800000>;
+		};
+	};
+};
+
+&cpu {
+	cpu-power-states = <&idle &s2ram>;
+};