boards/stm32: adapt default i2c config for stm32l5
boards/stm32: adapt default i2c config for stm32l5

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