audio: Stub out AudOutU::ListAudioOuts.

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

@@ -0,0 +1,17 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/hle/ipc_helpers.h"
+#include "core/hle/service/audio/audio.h"
+#include "core/hle/service/audio/audout_u.h"
+
+namespace Service {
+namespace Audio {
+
+void InstallInterfaces(SM::ServiceManager& service_manager) {
+    std::make_shared<AudOutU>()->InstallAsService(service_manager);
+}
+
+} // namespace Audio
+} // namespace Service