service/audio: Add missing services

Adds the missing audctl service, as well as the :a and :d services for
audin, audout, audrec, and audren.

src/core/hle/service/audio/audctl.h

@@ -0,0 +1,16 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/service/service.h"
+
+namespace Service::Audio {
+
+class AudCtl final : public ServiceFramework<AudCtl> {
+public:
+    explicit AudCtl();
+};
+
+} // namespace Service::Audio