Once you enable amd-pstate as mentioned in this thread:
https://forum.endeavouros.com/t/how-to-use-amd-p-state-in-linux-5-17/25247/8
Install cpupower, then edit the file:
$ /etc/default/cpupower
# Define CPUs governor
# valid governors: ondemand, performance, powersave, conservative, userspace.
governor='ondemand'
Then enable/start the service: cpupower.service