bsolos

Results 2 issues of bsolos

Use libdrm_amdgpu to calculate the GPU load. This should resolve #923. The GPU load calculation method was inspired by [radeontop](https://github.com/clbr/radeontop), but no code in this PR was copied from there.

GPU utilization always shows 100% even when idling. I'm sure it isn't MangoHud's fault, because `/sys/class/drm/card0/device/gpu_busy_percent` is `100` all the time too. [I've seen this issue already mentioned here](https://gitlab.freedesktop.org/drm/amd/-/issues/1932) 10...