move usb core into Adafruit_TinyUSB_core folder

Author: hathach

cores/nRF5/Arduino.h

@@ -68,11 +68,7 @@ void suspendLoop(void);
 #include "utility/AdaCallback.h"
 
 #ifdef NRF52840_XXAA
-  #include "tusb.h"
-#ifdef __cplusplus
-  #include "Adafruit_USBDevice.h"
-  #include "Adafruit_USBDev_CDC.h"
-#endif
+  #include "Adafruit_TinyUSB_core.h"
 #endif
 
 // Include board variant

cores/nRF5/usb/Adafruit_TinyUSB_core/Adafruit_TinyUSB_core.h

@@ -0,0 +1,35 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef ADAFRUIT_TINYUSB_CORE_H_
+#define ADAFRUIT_TINYUSB_CORE_H_
+
+#include "tusb.h"
+
+#ifdef __cplusplus
+#include "Adafruit_USBDevice.h"
+#include "Adafruit_USBDev_CDC.h"
+#endif
+
+#endif /* ADAFRUIT_TINYUSB_CORE_H_ */