cpu/stm32: rtc_f1.c: remove executable bit
cpu/stm32: rtc_f1.c: remove executable bit

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