Many thanks to Tino <tinotom@gmail.com> for drawing my attention to
this, for doing a lot of testing and providing great feedback.
Many thanks to AMD for continuing to release public specifications for
their chipsets.
PR: kern/157568
Tested by: Tino <tinotom@gmail.com>
MFC after: 1 week
The hardware is compliant with WDRT specification, so I originally
considered including generic WDRT watchdog support, but decided
against it, because I couldn't find anyone to the code for me.
WDRT seems to be not very popular.
Besides, generic WDRT porbably requires a slightly different driver
approach.
Reviewed by: des, gavin, rpaulo
MFC after: 3 weeks
