Update file header at TARGET_NRF52 level

 - Update (c) year and company name
 - Add SPDX-License-Identifier
 - Impacted files:
    - Files touched for SDK15 port
    - Files added in 2018

Author: TacoGrandeTX

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/PeripheralPinsDefault.c

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2018 ARM Limited
+ * Copyright (c) 2018 ARM Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/analogin_api.c

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
+ * Copyright (c) 2016-2018 Arm Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/common_rtc.h

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2015 ARM Limited
+ * Copyright (c) 2015-2018 ARM Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/gpio_api.c

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
+ * Copyright (c) 2006-2018 ARM Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/object_owners.c

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2018 ARM Limited
+ * Copyright (c) 2018 ARM Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/pinmap_ex.c

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2018 ARM Limited
+ * Copyright (c) 2018 ARM Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/pinmap_ex.h

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2018 ARM Limited
+ * Copyright (c) 2018 ARM Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/sleep.c

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
+ * Copyright (c) 2006-2018 Arm Limited and affiliates.
+ * 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.

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/us_ticker.h

@@ -1,5 +1,6 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2018 ARM Limited
+ * Copyright (c) 2018 ARM Limited and affiliates.
+ * 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.