cpu/stm32: add transition phase when raising +80MHz clock
cpu/stm32: add transition phase when raising +80MHz clock

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