make: allow override of RESET for boards/common/stm32f103c8
make: allow override of RESET for boards/common/stm32f103c8

kaspar030/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,toonst/RIOT,ant9000/RIOT,authmillenon/RIOT,josephnoir/RIOT,OTAkeys/RIOT,josephnoir/RIOT,kYc0o/RIOT,OTAkeys/RIOT,rfuentess/RIOT,basilfx/RIOT,miri64/RIOT,RIOT-OS/RIOT,josephnoir/RIOT,cladmi/RIOT,rfuentess/RIOT,x3ro/RIOT,aeneby/RIOT,basilfx/RIOT,aeneby/RIOT,jasonatran/RIOT,ant9000/RIOT,jasonatran/RIOT,ant9000/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,OlegHahm/RIOT,x3ro/RIOT,yogo1212/RIOT,yogo1212/RIOT,kaspar030/RIOT,yogo1212/RIOT,x3ro/RIOT,smlng/RIOT,x3ro/RIOT,smlng/RIOT,aeneby/RIOT,mtausig/RIOT,rfuentess/RIOT,aeneby/RIOT,rfuentess/RIOT,josephnoir/RIOT,cladmi/RIOT,josephnoir/RIOT,authmillenon/RIOT,mtausig/RIOT,authmillenon/RIOT,kYc0o/RIOT,yogo1212/RIOT,smlng/RIOT,cladmi/RIOT,toonst/RIOT,authmillenon/RIOT,basilfx/RIOT,jasonatran/RIOT,authmillenon/RIOT,kaspar030/RIOT,smlng/RIOT,aeneby/RIOT,mtausig/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,OlegHahm/RIOT,ant9000/RIOT,mtausig/RIOT,miri64/RIOT,OTAkeys/RIOT,miri64/RIOT,OlegHahm/RIOT,yogo1212/RIOT,x3ro/RIOT,kaspar030/RIOT,kYc0o/RIOT,miri64/RIOT,basilfx/RIOT,kYc0o/RIOT,toonst/RIOT,toonst/RIOT,miri64/RIOT,mtausig/RIOT,ant9000/RIOT,cladmi/RIOT,RIOT-OS/RIOT,rfuentess/RIOT,jasonatran/RIOT,OlegHahm/RIOT,smlng/RIOT,cladmi/RIOT,kYc0o/RIOT,basilfx/RIOT,yogo1212/RIOT,OTAkeys/RIOT,toonst/RIOT