librtc: work-in-progress

Remaining Tasks:

 - Validate input.

 - Maybe it might be better to put this into readclock and have that
 running all of the time?
readclock: work-in-progress

Need working RTC for PMIC power-off. This commit is a first pass
at implementing support for the RTC in the AM335X SoC in readclock.
To support the xM, a driver for the xM's PMIC needs to be written.

Remaining Tasks:

 - There was some refactoring that went on to split the i386
 code into it's own file. Need to test on i386 to ensure nothing
 broke.

 - Update rc script to use readclock on ARM. Need to test on
 BeagleBoard-xM to ensure nothing breaks there.

 - Need to test on BeagleBone White.

Change-Id: I850649214f5601ffaaa9794d2bad4df1ec4b382c
tps65217: work in progress

Remaining Tasks:

 - Probably need to factor out do_shutdown into libsys.

 - Lots of clean-up (especially in the interrupt handler). There's
 a lot of test and debugging code in there that does bad things.
kernel: work-in-progress