l2util: add l2util_addr_equal()
l2util: add l2util_addr_equal()

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