[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

manifest-pr-skip

Signed-off-by: Sebastian Głąb <sebastian.glab@nordicsemi.no>

dts/common/nordic/nrf54h20.dtsi

@@ -28,6 +28,7 @@
  device_type = "cpu";
  clocks = <&cpuapp_hsfll>;
  clock-frequency = <DT_FREQ_M(320)>;
+ cpu-power-states = <&idle &s2ram>;
  };
 
  cpurad: cpu@3 {
@@ -72,6 +73,20 @@
  nordic,tasks-mask = <0xfffffff0>;
  };
  };
+
+ 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>;
+ };
+ };
  };
 
  reserved-memory {