cc26x2_cc13x2: add AON_RTC definitions
cc26x2_cc13x2: add AON_RTC definitions

Signed-off-by: Jean Pierre Dudey <341388fa1817ca285e65547384a9727ce7f6d39a@hotmail.com>

ant9000/RIOT,kaspar030/RIOT,kYc0o/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,jasonatran/RIOT,miri64/RIOT,authmillenon/RIOT,miri64/RIOT,OlegHahm/RIOT,authmillenon/RIOT,kYc0o/RIOT,miri64/RIOT,jasonatran/RIOT,OTAkeys/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,basilfx/RIOT,yogo1212/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,OTAkeys/RIOT,yogo1212/RIOT,authmillenon/RIOT,miri64/RIOT,jasonatran/RIOT,OlegHahm/RIOT,kaspar030/RIOT,authmillenon/RIOT,OTAkeys/RIOT,ant9000/RIOT,basilfx/RIOT,ant9000/RIOT,basilfx/RIOT,basilfx/RIOT,miri64/RIOT,yogo1212/RIOT,ant9000/RIOT,yogo1212/RIOT,OlegHahm/RIOT,authmillenon/RIOT,ant9000/RIOT,kYc0o/RIOT,OlegHahm/RIOT,yogo1212/RIOT,jasonatran/RIOT,kaspar030/RIOT,kaspar030/RIOT,OTAkeys/RIOT,basilfx/RIOT,OTAkeys/RIOT