tests: power management: test_power_state_trans fails on nrf boards

[PerMac]

Describe the bug
The test test_power_state_trans from tests/subsys/power/power_mgmt/ fails on-target tests (at least on nrf and reel boards)

To Reproduce
Steps to reproduce the behavior:

1. have nrf52840dk connected
2. go to your zephyr dir
3. call /scripts/twister -T /tests/subsys/power/power_mgmt -p nrf52840dk_nrf52840 --device-testing --device-serial /dev/ttyACM0 -v --inline-logs
4. See error

Expected behavior
The test passes

Impact
Not clear

Logs and console output

START - test_power_state_trans
Assertion failed at WEST_TOPDIR/zephyr/tests/subsys/power/power_mgmt/src/main.c:109: notify_pm_state_exit: (notify_app_exit == true is false)
Notification to leave suspend was not sent to the App
Assertion failed at WEST_TOPDIR/zephyr/tests/subsys/power/power_mgmt/src/main.c:112: notify_pm_state_exit: state not equal to PM_STATE_RUNTIME_IDLE
FAIL - test_power_state_trans in 0.133 seconds

Environment (please complete the following information):

• OS: Ubuntu 18.04
• Toolchain Zephyr SDK 0.12.2
• Commit SHA or Version used: zephyr-v2.5.0-3011-gb61c23943c6f

[PerMac]

I think the same bug is causing more power mgmt tests/samples to fail, as I see also this one failing from the same time: sample.power.ospm.dev_idle_pm

[PerMac]

@gmarull The fail of test_power_state_trans is gone, thanks. Do you know if sample.power.ospm.dev_idle_pm (samples/subsys/pm) is related? Should I raise a separate issue? This test is still failing with the fix (nrf52840 and nrf52832). It hangs at:

ERROR   - *** Booting Zephyr OS build zephyr-v2.5.0-3821-g41afd838aabd  ***
Device PM sample app start
open()
parent resuming..
Async wakeup request queued
child resuming..
Dummy device resumed
write()
transfer()
read()
transfer()
close()
child suspending..
Device PM sample app complete
parent suspending..

[gmarull]

@ceolin do you know if related to any recent change?

[gmarull]

@PerMac #35315 may fix the problem, but I haven't reviewed yet

[PerMac]

unluckily, #35315 doesn't change the test behavior. A separate issue for ease of tracking #35336