boards/common/slwstk6000b: Add Kconfig symbols
boards/common/slwstk6000b: Add Kconfig symbols

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