tests/l2util: remove mention to nordic-softdevice-ble
tests/l2util: remove mention to nordic-softdevice-ble

ant9000/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,OlegHahm/RIOT,kaspar030/RIOT,OTAkeys/RIOT,ant9000/RIOT,OlegHahm/RIOT,jasonatran/RIOT,miri64/RIOT,OTAkeys/RIOT,authmillenon/RIOT,miri64/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,ant9000/RIOT,RIOT-OS/RIOT,ant9000/RIOT,kYc0o/RIOT,OTAkeys/RIOT,jasonatran/RIOT,miri64/RIOT,jasonatran/RIOT,OlegHahm/RIOT,miri64/RIOT,OlegHahm/RIOT,ant9000/RIOT,authmillenon/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,miri64/RIOT,jasonatran/RIOT,OlegHahm/RIOT,kaspar030/RIOT,OTAkeys/RIOT,kYc0o/RIOT,jasonatran/RIOT,OTAkeys/RIOT,authmillenon/RIOT,kYc0o/RIOT,kaspar030/RIOT,kYc0o/RIOT,kYc0o/RIOT,authmillenon/RIOT,kaspar030/RIOT