Take a look at the Quark datasheet Intel® Quark SoC — X1000 Datasheet section 2.12. Here you’ll find some information on the RTC signals. Section 21.10 also contains information on the RTC, such as signal description characteristics, interrupts, features and register maps.
Now as for the access methods for the registers go to section 5 “Register Access Methods”.
You can also find useful information in Intel® Quark SoC — Intel® Quark SoC Software Developer's Manual for Linux*