makefiles/dfu-util: Update dfu-util.inc.mk for DFU bootloader
makefiles/dfu-util: Update dfu-util.inc.mk for DFU bootloader

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