Support to change PowerMizer in Wayland

[fhilipecrash]

I wanted to configure my GPU through nvidia-settings to leave PowerMizer at Max Performace, not only PowerMizer but it would be great if nvidia-settings had all the X11 options available in Wayland as well. I don't know if setting PowerMizer in X11 keeps the configuration in Wayland but even so it's still good if nvidia-settings is 100% functional in Wayland.

[HorstBaerbel]

You might want to chime in on issue #69