Backport fixes from nordic branches:

- nrf headers synchronized with the one in BLE implementation. This is a
  short term fix. The nordic branches use a single nrf SDK and does not
  have duplicate headers. Once this branch will be integrated, there will
  be no more issues around duplicate headers.
- enable feature BLE in the targets.json. This fix was done a long time
  ago in the nordic branch. Without it, it is not possible to compile BLE
  examples.

Author: pan-

hal/targets.json

@@ -1105,7 +1105,8 @@
             "toolchains": ["ARM_STD", "GCC_ARM"]
         },
         "program_cycle_s": 6,
-        "default_build": "small"
+        "default_build": "small",
+        "features": ["BLE"]
     },
     "MCU_NRF51_16K_BASE": {
         "inherits": ["MCU_NRF51"],

hal/targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/nrf.h

@@ -1,48 +1,61 @@
-/* Copyright (c) 2013, Nordic Semiconductor ASA
+/*
+ * Copyright (c) Nordic Semiconductor ASA
  * All rights reserved.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
  *
- *   * Redistributions of source code must retain the above copyright notice, this
- *     list of conditions and the following disclaimer.
+ *   1. Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
  *
- *   * Redistributions in binary form must reproduce the above copyright notice,
- *     this list of conditions and the following disclaimer in the documentation
- *     and/or other materials provided with the distribution.
+ *   2. Redistributions in binary form must reproduce the above copyright notice, this
+ *   list of conditions and the following disclaimer in the documentation and/or
+ *   other materials provided with the distribution.
  *
- *   * Neither the name of Nordic Semiconductor ASA nor the names of its
- *     contributors may be used to endorse or promote products derived from
- *     this software without specific prior written permission.
+ *   3. Neither the name of Nordic Semiconductor ASA nor the names of other
+ *   contributors to this software may be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
+
 #ifndef NRF_H
 #define NRF_H
 
-#ifndef _WIN32
-
-/* Family selection for main includes. NRF51 must be selected. */
-#ifdef NRF51
-    #include "nrf51.h"
-    #include "nrf51_bitfields.h"
+#if defined(_WIN32)
+    /* Do not include nrf51 specific files when building for PC host */
+#elif defined(__unix)
+    /* Do not include nrf51 specific files when building for PC host */
+#elif defined(__APPLE__)
+    /* Do not include nrf51 specific files when building for PC host */
 #else
-    #error "Device family must be defined. See nrf.h."
-#endif /* NRF51 */
 
-#include "compiler_abstraction.h"
+    /* Family selection for family includes. */
+    #if defined (NRF51)
+        #include "nrf51.h"
+        #include "nrf51_bitfields.h"
+        #include "nrf51_deprecated.h"
+    #elif defined (NRF52)
+        #include "nrf52.h"
+        #include "nrf52_bitfields.h"
+        #include "nrf51_to_nrf52.h"
+    #else
+        #error "Device family must be defined. See nrf.h."
+    #endif /* NRF51, NRF52 */
 
-#endif /* _WIN32 */
+    #include "compiler_abstraction.h"
 
-#endif /* NRF_H */
+#endif /* _WIN32 || __unix || __APPLE__ */
 
+#endif /* NRF_H */