Intel iGPU, `xe` kernel driver: nvtop reports `cur_freq` (requested frequency) instead of `act_freq` (actual frequency)

For at least Intel iGPUs using the xe kernel driver, and likely the i915 driver as well, nvtop reports the value from cur_freq as the actual GPU frequency when Intel uses this as the "requested frequency" and use act_freq as the "actual frequency" the GPU is currently operating at.

For better accuracy, it would be nice if nvtop could report act_freq for the GPU frequency with Intel GPUs.

I noticed this issue when comparing nvtop with qmassa.

Below is the qmassa issue where ulissesf (qmassa's developer) helped explain why I was seeing different values with each tool:

https://github.com/ulissesf/qmassa/issues/35#issuecomment-4090592954