frdm-k64f: Add configuration for dedicated analog pins
frdm-k64f: Add configuration for dedicated analog pins

These pins have no alternate function in the pin mux so we might as well
make them available to applications. These pins are the only pins which
provide differential analog input pairs on this board.

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