SB7xx watchdog: new driver for review and testing

[Andriy Gapon]

Please review and/or test a new driver for watchdog driver included into AMD SB7xx:
http://people.freebsd.org/~avg/amdsbwd.tgz
I have tested this driver only with SB700 on Gigabyte GA-MA780G-UD3H motherboard.

ichwd driver was used as a starting point for this driver. This can be seen from
some function names, general code organization and some small code snippets.
Many thanks to ichwd authors and maintainers!

Right now I have infrastructure only for building this driver as a module.

Things for which that I need the most feedback/ideas:
1. If the driver actually works on your hardware and the hardware description.
The driver can be tested by loading the driver and doing 'watchdog -t <small
number>'. Having debug.bootverbose=1 may provide additional useful info.
And better to test this from single-user mode with filesystems mounted r/o.

2. Better name for the driver. amdsbwd stands for "AMD S(outh)B(ridge)
WatchDog", but this abbreviation could be cryptic to decipher.

3. Proper location for this driver.
At least on my system this driver needs resources (I/O ports and MEM range) that
are claimed by ACPI, thus I've made it a child of acpi bus. But this driver
doesn't have anything else ACPI-ish in it, so I decided that it doesn't belong
under acpica/ or acpi_support/. Am I correct about this?

Anything else you would like to report or comment or advise to me.
Thank you very much for your help.

-- 
Andriy Gapon