cpu/stm32: fix missing clock configuration defines for g0
cpu/stm32: fix missing clock configuration defines for g0

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