Rebased on master mbed-os 9/7/18

This required replacing hal_tick.h with us_ticker_data.h

targets/TARGET_STM/TARGET_STM32L4/TARGET_MTS_DRAGONFLY_L471QG/device/us_ticker_data.h

@@ -0,0 +1,45 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2018 ARM Limited
+ *
+ * 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 __US_TICKER_DATA_H
+#define __US_TICKER_DATA_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+#include "stm32l4xx.h"
+#include "stm32l4xx_ll_tim.h"
+#include "cmsis_nvic.h"
+   
+#define TIM_MST      TIM5
+#define TIM_MST_IRQ  TIM5_IRQn
+#define TIM_MST_RCC  __HAL_RCC_TIM5_CLK_ENABLE()
+#define TIM_MST_DBGMCU_FREEZE  __HAL_DBGMCU_FREEZE_TIM5()
+
+#define TIM_MST_RESET_ON   __HAL_RCC_TIM5_FORCE_RESET()
+#define TIM_MST_RESET_OFF  __HAL_RCC_TIM5_RELEASE_RESET()
+
+#define TIM_MST_BIT_WIDTH  32 // 16 or 32
+
+#define TIM_MST_PCLK  1 // Select the peripheral clock number (1 or 2)
+
+#define HAL_TICK_DELAY (1000) // 1 ms
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // __US_TICKER_DATA_H