drivers/include/hts221.h : Remove ifndef for I2C
drivers/include/hts221.h : Remove ifndef for I2C

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