hle: Add service stubs for apm and appletOE.

src/core/hle/service/apm/apm.h

@@ -0,0 +1,22 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/service/service.h"
+
+namespace Service {
+namespace APM {
+
+class APM final : public ServiceFramework<APM> {
+public:
+    explicit APM();
+    ~APM();
+};
+
+/// Registers all AM services with the specified service manager.
+void InstallInterfaces(SM::ServiceManager& service_manager);
+
+} // namespace APM
+} // namespace Service