Fixed the unittest case failure

UNITTESTS/target_h/drivers/Ticker.h

@@ -0,0 +1,52 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_TICKER_H
+#define MBED_TICKER_H
+#include "drivers/TimerEvent.h"
+#include "platform/Callback.h"
+
+namespace mbed {
+/** \addtogroup drivers */
+
+/** mock Ticker
+ *
+ */
+class Ticker {
+
+public:
+    Ticker()
+    {
+    }
+
+    void attach_us(Callback<void()> func, us_timestamp_t t)
+    {
+
+    }
+
+    void detach()
+    {
+
+    }
+
+    ~Ticker()
+    {
+    }
+};
+
+} // namespace mbed
+
+#endif

UNITTESTS/target_h/platform/mbed_power_mgmt.h

@@ -19,9 +19,14 @@
  *
  * @note Does not affect the debug sub-system
  */
+#ifndef MBED_POWER_MGMT_H
+#define MBED_POWER_MGMT_H
 extern void mock_system_reset();
 
 MBED_NORETURN static inline void system_reset(void)
 {
     mock_system_reset();
 }
+
+#endif
+