sys/shell/commands: add i2c_scanner deps to Kconfig
sys/shell/commands: add i2c_scanner deps to Kconfig

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