RTC subsystem

 Hello,

  updated version of my proposal for an RTC Subsystem. 

 I've fixed some locking issues, thanks to Dmitry Torokhov
 and added a driver for the Dallas/Maxim DS1672 Timekeeping
 chip.

 The subsystem should now be capable to handle all
 of the existing standalone drivers. 

 As usual, your feedback is highly appreciated.

--

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Turin, Italy

  http://www.towertech.it