drivers: nrf: Clean up remnants of nrfx error codes Starting with nrfx 4.0.0, the nrfx_err_t, NRFX_SUCCESS and NRFX_ERROR_* have been deprecated. Most of them were removed here: https://github.com/zephyrproject-rtos/zephyr/pull/99399 but a few were missed. Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>