hwmon: (k10temp) Don't show temperature limits on Ryzen (Zen) CPUs

The maximum Tdie or Tctl is not published for Ryzen CPUs. What is
known, however, is that the traditional value of 70 degrees C is no
longer correct. On top of that, the limit applies to Tctl, not to Tdie.
Displaying it in either context is meaningless, confusing, and wrong.
Stop doing it.

Tested-by: Brad Campbell <lists2009@fnarfbargle.com>
Tested-by: Holger Kiehl <holger.kiehl@dwd.de>
Tested-by: Michael Larabel <michael@phoronix.com>
Tested-by: Jonathan McDowell <noodles@earth.li>
Tested-by: Ken Moffat <zarniwhoop73@googlemail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>