samples: tests: Tests from samples/boards/nrf/nrfx fail

[PerMac]

Describe the bug
Tests from samples/boards/nrf/nrfx fail twister tests with timeout. It happens because the tests were not designed properly: there are no actual tests defined (no pass/fail conditions).

Impact
Annoyance

Environment (please complete the following information):

OS: Ubuntu 18.04
Toolchain Zephyr SDK
Commit SHA or Version used v2.5.0-rc3-39-gd0be253081f5