[nrf fromlist] tests: mbox: Add support for nRF54LM20A#3141

rlubos merged 1 commit intonrfconnect:mainnrfconnect/sdk-zephyr:mainfrom

kl-cruz:mbox_test_lm20a_pickkl-cruz/sdk-zephyr:mbox_test_lm20a_pickCopy head branch name to clipboard