tests/ztimer_periodic: fix name clash with rp2040 vendor header
tests/ztimer_periodic: fix name clash with rp2040 vendor header

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