pkg/minmea: add minmea_getdate()
pkg/minmea: add minmea_getdate()

Add a fucntion to expose the internal `struct tm` that is populated
with the GPS date.

This allows for easy syncing the RTC with the GPS time without having
to convert back and forth between `struct tm` and `time_t`.

    struct tm now;
    minmea_getdate(&now, data, time);
    rtc_set_time(&now)

upstream PR: https://github.com/kosma/minmea/pull/45

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