boards/hifive1: fix file permissions of flasher.sh
boards/hifive1: fix file permissions of flasher.sh

BytesGalore/RIOT,cladmi/RIOT,BytesGalore/RIOT,authmillenon/RIOT,cladmi/RIOT,kaspar030/RIOT,rfuentess/RIOT,authmillenon/RIOT,authmillenon/RIOT,OTAkeys/RIOT,lazytech-org/RIOT,toonst/RIOT,aeneby/RIOT,miri64/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,authmillenon/RIOT,josephnoir/RIOT,ant9000/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,lazytech-org/RIOT,smlng/RIOT,miri64/RIOT,yogo1212/RIOT,lazytech-org/RIOT,mfrey/RIOT,OTAkeys/RIOT,smlng/RIOT,A-Paul/RIOT,ant9000/RIOT,kYc0o/RIOT,mtausig/RIOT,josephnoir/RIOT,aeneby/RIOT,mtausig/RIOT,ant9000/RIOT,basilfx/RIOT,mfrey/RIOT,mtausig/RIOT,jasonatran/RIOT,smlng/RIOT,kYc0o/RIOT,jasonatran/RIOT,kaspar030/RIOT,mfrey/RIOT,aeneby/RIOT,rfuentess/RIOT,OlegHahm/RIOT,BytesGalore/RIOT,A-Paul/RIOT,miri64/RIOT,kYc0o/RIOT,kaspar030/RIOT,mtausig/RIOT,kaspar030/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,miri64/RIOT,yogo1212/RIOT,A-Paul/RIOT,toonst/RIOT,kaspar030/RIOT,cladmi/RIOT,josephnoir/RIOT,ant9000/RIOT,RIOT-OS/RIOT,mtausig/RIOT,miri64/RIOT,lazytech-org/RIOT,OTAkeys/RIOT,ant9000/RIOT,cladmi/RIOT,A-Paul/RIOT,rfuentess/RIOT,yogo1212/RIOT,OlegHahm/RIOT,basilfx/RIOT,aeneby/RIOT,authmillenon/RIOT,toonst/RIOT,yogo1212/RIOT,rfuentess/RIOT,A-Paul/RIOT,mfrey/RIOT,kYc0o/RIOT,x3ro/RIOT,jasonatran/RIOT,x3ro/RIOT,basilfx/RIOT,BytesGalore/RIOT,cladmi/RIOT,basilfx/RIOT,x3ro/RIOT,OlegHahm/RIOT,smlng/RIOT,rfuentess/RIOT,toonst/RIOT,x3ro/RIOT,jasonatran/RIOT,josephnoir/RIOT,x3ro/RIOT,BytesGalore/RIOT,basilfx/RIOT,smlng/RIOT,RIOT-OS/RIOT,toonst/RIOT,mfrey/RIOT,josephnoir/RIOT,yogo1212/RIOT,lazytech-org/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,aeneby/RIOT,OTAkeys/RIOT,kYc0o/RIOT