nrf51dk: Enable the nRF51 built-in DC/DC converter
nrf51dk: Enable the nRF51 built-in DC/DC converter

jasonatran/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,basilfx/RIOT,authmillenon/RIOT,kaspar030/RIOT,kYc0o/RIOT,yogo1212/RIOT,ant9000/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,miri64/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,yogo1212/RIOT,authmillenon/RIOT,kaspar030/RIOT,OTAkeys/RIOT,OTAkeys/RIOT,kYc0o/RIOT,OTAkeys/RIOT,authmillenon/RIOT,basilfx/RIOT,authmillenon/RIOT,basilfx/RIOT,basilfx/RIOT,basilfx/RIOT,OTAkeys/RIOT,OTAkeys/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,ant9000/RIOT,yogo1212/RIOT,jasonatran/RIOT,miri64/RIOT,jasonatran/RIOT,kaspar030/RIOT,miri64/RIOT,ant9000/RIOT,OlegHahm/RIOT,ant9000/RIOT,jasonatran/RIOT,kaspar030/RIOT,kYc0o/RIOT,kaspar030/RIOT,authmillenon/RIOT,kYc0o/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,miri64/RIOT,yogo1212/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,yogo1212/RIOT,ant9000/RIOT,miri64/RIOT