samples: boards: nordic: system_off: sample.boards.nrf.system_off.* fail

[katgiadla]

Describe the bug
Samples:

• sample.boards.nrf.system_off.lpcomp_wakeup
• sample.boards.nrf.system_off.retained_mem.lpcomp_wakeup

do not work.

Observed for nrf54l15dk/nrf54l15/cpuapp.

Sample sample.boards.nrf.system_off.retained_mem.grtc_wakeup does not work on nrf54l15dk/nrf54l10/cpuapp.

To Reproduce
Steps to reproduce the behavior:

1. have nrf54l15dk/nrf54l15/cpuapp connected
2. go to your zephyr dir
3. call ./scripts/twister -T samples/boards/nordic/system_off -p nrf54l15dk/nrf54l15/cpuapp --device-testing --device-serial /dev/ttyACM1 -v --inline-logs --west-flash="--erase"
4. See console output with error

Expected behavior
Valid console output

Impact
Not clear

Logs and console output

Logs for sample.boards.nrf.system_off.lpcomp_wakeup[nrf54l15dk/nrf54l15/cpuapp]:

*** Booting Zephyr OS build v4.0.0-3190-g99a63a776980 ***

nrf54l15dk system off demo
Retained data not supported
Entering system off; change signal level at comparator input to restart

Logs for sample.boards.nrf.system_off.retained_mem.lpcomp_wakeup[nrf54l15dk/nrf54l15/cpuapp] and sample.boards.nrf.system_off.retained_mem.grtc_wakeup[nrf54l15dk/nrf54l10/cpuapp]:

*** Booting Zephyr OS build v4.0.0-3190-g99a63a776980 ***

nrf54l15dk system off demo
Retained data: INVALID
Boot count: 1
Off count: 0
Active Ticks: 13621
Entering system off; change signal level at comparator input to restart

Environment (please complete the following information):

• OS: Ubuntu 20.04.1 LTS
• Toolchain: Zephyr SDK 0.17.0
• Commit SHA or Version used: v4.0.0-3067-g910ec5