boards/nucleo-f207zg: fix nucleo common Kconfig
boards/nucleo-f207zg: fix nucleo common Kconfig

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