[nrf fromlist] soc: nordic: nrf54h: disable IRQ before PM config

IRQs must be disabled before starting any procedures to prepare
for low-power states.

Upstream PR #: 79067

Signed-off-by: Adam Kondraciuk <adam.kondraciuk@nordicsemi.no>

soc/nordic/nrf54h/pm_s2ram.c

@@ -111,18 +111,16 @@ int soc_s2ram_suspend(pm_s2ram_system_off_fn_t system_off)
 {
 	int ret;
 
-	__disable_irq();
 	nvic_suspend(&backup_data.nvic_context);
 	mpu_suspend(&backup_data.mpu_context);
 	ret = arch_pm_s2ram_suspend(system_off);
 	if (ret < 0) {
-		__enable_irq();
+		/* On resuming or error we return exactly *HERE* */
 		return ret;
 	}
 
 	mpu_resume(&backup_data.mpu_context);
 	nvic_resume(&backup_data.nvic_context);
-	__enable_irq();
 
 	return ret;
 }

soc/nordic/nrf54h/power.c

@@ -188,14 +188,16 @@ static void s2ram_enter(void)
 void pm_state_set(enum pm_state state, uint8_t substate_id)
 {
 	if (state == PM_STATE_SUSPEND_TO_IDLE) {
+		__disable_irq();
 		s2idle_enter(substate_id);
 		/* Resume here. */
 		s2idle_exit(substate_id);
 	}
 #if defined(CONFIG_PM_S2RAM)
 	else if (state == PM_STATE_SUSPEND_TO_RAM) {
+		__disable_irq();
 		s2ram_enter();
-		/* On resuming or error we return exactly *HERE* */
+		/* Resume here. */
 		s2ram_exit();
 	}
 #endif
@@ -206,5 +208,5 @@ void pm_state_set(enum pm_state state, uint8_t substate_id)
 
 void pm_state_exit_post_ops(enum pm_state state, uint8_t substate_id)
 {
-	irq_unlock(0);
+	__enable_irq();
 }