cpu/native: extend flashpage API
cpu/native: extend flashpage API

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