Change the RTC drivers so that the rtc_(read|write)_datetime functions now deal directly with the tm struct instead of passing a string of bcd digits to/from (set|get)_time .
This simplifies drivers for rtc's that do not use a bcd representation internally and cleans up some target specific code and #ifdefs in generic code. Implement simple stubs for the sim to avoid #ifdefing for that too.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22839 a1c6a512-1295-4272-9138-f99709370657
