Have GetActiveChannelCount return the system channels instead of host device channels

src/core/hle/service/audio/audren_u.cpp

@@ -359,7 +359,7 @@ private:
 
     void GetActiveChannelCount(HLERequestContext& ctx) {
         const auto& sink{system.AudioCore().GetOutputSink()};
-        u32 channel_count{sink.GetDeviceChannels()};
+        u32 channel_count{sink.GetSystemChannels()};
 
         LOG_DEBUG(Service_Audio, "(STUBBED) called. Channels={}", channel_count);