service/audren_u: Handle audio USB output revision queries in ListAudioDeviceName()

Audio devices use the supplied revision information in order to
determine if USB audio output is able to be supported. In this case, we
can only really handle using this revision information in
ListAudioDeviceName(), where it checks if USB audio output is supported
before supplying it as a device name.

A few other scenarios exist where the revision info is checked, such as:

- Early exiting from SetAudioDeviceOutputVolume if USB audio is
  attempted to be set when that device is unsupported.

- Early exiting and returning 0.0f in GetAudioDeviceOutputVolume when
  USB output volume is queried and it's an unsupported device.

- Falling back to AHUB headphones in GetActiveAudioDeviceName when the
  device type is USB output, but is unsupported based off the revision
  info.

In order for these changes to also be implemented, a few other changes
to the interface need to be made.

Given we now properly handle everything about ListAudioDeviceName(), we
no longer need to describe it as a stubbed function.