boards/nrf52840dongle: enable DCDC converters
boards/nrf52840dongle: enable DCDC converters

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