nucleo-f302r8: remove obsolete spi_divtable
nucleo-f302r8: remove obsolete spi_divtable

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