Annotate session interfaces with CAP_QUOTA

The new 'CAP_QUOTA' enum value denotes the capability quota to be
transferred from the client to the server at session-creation time.

Issue #2398

repos/os/include/file_system_session/connection.h

@@ -48,11 +48,13 @@ struct File_system::Connection_base : Genode::Connection<Session>, Session_clien
 	{
 		return session(parent,
 		               "ram_quota=%ld, "
+		               "cap_quota=%ld, "
 		               "tx_buf_size=%ld, "
 		               "label=\"%s\", "
 		               "root=\"%s\", "
 		               "writeable=%d",
 		               8*1024*sizeof(long) + tx_buf_size,
+		               CAP_QUOTA,
 		               tx_buf_size,
 		               label, root, writeable);
 	}

repos/os/include/file_system_session/file_system_session.h

@@ -256,6 +256,8 @@ struct File_system::Session : public Genode::Session
 
 	static const char *service_name() { return "File_system"; }
 
+	enum { CAP_QUOTA = 5 };
+
 	virtual ~Session() { }
 
 	/**