fix: cpu temp now reads correctly on linux

[insberr]

CPU temp (cpu_temp) is read from /sys/class/thermal/thermal_zone0/temp and falls back to /sys/class/hwmon/hwmon0/temp1_input, however the devices at hwmon can vary across systems/boots. For example, on my system hwmon0 is my nvme.

This is a simple fix that iterates over /sys/class/hwmon/ devices to find the k10temp or zenpower driver (whichever it finds first) which yield the tdie CPU temp.

Fixes #128

[valpackett]

Right, we need to do the same for the thermal zones as well tho! :D

Can you make the iteration function reusable for both? And cache the path after it's been found once, or even better, keep the file descriptor and reread from it on further invocations.

[insberr]

It completely passed over me that /sys/class/thermal might need to be searched too, haha. Should be taken care of now! Also kept the file descriptor for future invocations.

Some additional testing might be required. My CPU temps are on hwmon so I cant really test thermal.

[valpackett]

Thanks!!

[insberr]

No problem!