hwmon: (k10temp) Take out debugfs code

The debugfs code was intended to aid figuring out functionality
of undocumented registers. Turns out that wasn't very helpful,
since register locations change too much between AMD chip revisions,
and the data isn't really valuable for chips where it isn't already
supported. On top of that, its existence has been used as argument
for providing pseudo-API debugfs functions in other drivers.
So let's just take it out.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>