cpu/lpc2387: enable full rtc_normalize() for RTC
cpu/lpc2387: enable full rtc_normalize() for RTC

The RTC actually makes use of the day of year / day of week fields,
so enable the calculation of those fields in rtc_normalize().

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