service: Add the grc:c service

Adds the basic skeleton for the grc:c service based off the information
provided by Switch Brew.

src/core/hle/service/grc/grc.h

@@ -0,0 +1,15 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+namespace Service::SM {
+class ServiceManager;
+}
+
+namespace Service::GRC {
+
+void InstallInterfaces(SM::ServiceManager& sm);
+
+} // namespace Service::GRC