[nrf fromtree] samples: tests: Add support to tests on nrf54l15 DK#2069

rlubos merged 2 commits intonrfconnect:mainnrfconnect/sdk-zephyr:mainfrom

katgiadla:nrf54l15dk_zephyrkatgiadla/sdk-zephyr:nrf54l15dk_zephyrCopy head branch name to clipboard