boards/samd21-xpro: fix attr order in i2c_config
boards/samd21-xpro: fix attr order in i2c_config

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