hwmon: (k10temp) Show core and SoC current and voltages on Ryzen CPUs

Ryzen CPUs report core and SoC voltages and currents. Add support
for it to the k10temp driver.

For the time being, only report voltages and currents for Ryzen
CPUs. Threadripper and EPYC appear to use a different mechanism.

Tested-by: Brad Campbell <lists2009@fnarfbargle.com>
Tested-by: Bernhard Gebetsberger <bernhard.gebetsberger@gmx.at>
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>
Tested-by: Darren Salt <devspam@moreofthesa.me.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>