Add unmodified Teensy files

BUILD file and modifications to sanify coming soon. These are unmodified
from Teensyduino 1.37 for change tracking purposes.

Change-Id: Id55e2eba0e03260d14ea58ae4c536ae271315164
diff --git a/motors/usb/usb_dev.h b/motors/usb/usb_dev.h
new file mode 100644
index 0000000..1233d7f
--- /dev/null
+++ b/motors/usb/usb_dev.h
@@ -0,0 +1,137 @@
+/* Teensyduino Core Library
+ * http://www.pjrc.com/teensy/
+ * Copyright (c) 2017 PJRC.COM, LLC.
+ *
+ * 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:
+ *
+ * 1. The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * 2. If the Software is incorporated into a build system that allows
+ * selection among a list of target devices, then similar target
+ * devices manufactured by PJRC.COM must be included in the list of
+ * target devices and selectable in the same manner.
+ *
+ * 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 _usb_dev_h_
+#define _usb_dev_h_
+
+#define USB_DESC_LIST_DEFINE
+#include "usb_desc.h"
+
+#if F_CPU >= 20000000 && !defined(USB_DISABLED)
+
+// This header is NOT meant to be included when compiling
+// user sketches in Arduino.  The low-level functions
+// provided by usb_dev.c are meant to be called only by
+// code which provides higher-level interfaces to the user.
+
+#include "usb_mem.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void usb_init(void);
+void usb_init_serialnumber(void);
+void usb_isr(void);
+usb_packet_t *usb_rx(uint32_t endpoint);
+uint32_t usb_tx_byte_count(uint32_t endpoint);
+uint32_t usb_tx_packet_count(uint32_t endpoint);
+void usb_tx(uint32_t endpoint, usb_packet_t *packet);
+void usb_tx_isochronous(uint32_t endpoint, void *data, uint32_t len);
+
+extern volatile uint8_t usb_configuration;
+
+extern uint16_t usb_rx_byte_count_data[NUM_ENDPOINTS];
+static inline uint32_t usb_rx_byte_count(uint32_t endpoint) __attribute__((always_inline));
+static inline uint32_t usb_rx_byte_count(uint32_t endpoint)
+{
+        endpoint--;
+        if (endpoint >= NUM_ENDPOINTS) return 0;
+        return usb_rx_byte_count_data[endpoint];
+}
+
+#ifdef CDC_DATA_INTERFACE
+extern uint32_t usb_cdc_line_coding[2];
+extern volatile uint32_t usb_cdc_line_rtsdtr_millis;
+extern volatile uint32_t systick_millis_count;
+extern volatile uint8_t usb_cdc_line_rtsdtr;
+extern volatile uint8_t usb_cdc_transmit_flush_timer;
+extern void usb_serial_flush_callback(void);
+#endif
+
+#ifdef SEREMU_INTERFACE
+extern volatile uint8_t usb_seremu_transmit_flush_timer;
+extern void usb_seremu_flush_callback(void);
+#endif
+
+#ifdef KEYBOARD_INTERFACE
+extern uint8_t keyboard_modifier_keys;
+extern uint8_t keyboard_keys[6];
+extern uint8_t keyboard_protocol;
+extern uint8_t keyboard_idle_config;
+extern uint8_t keyboard_idle_count;
+extern volatile uint8_t keyboard_leds;
+#endif
+
+#ifdef MIDI_INTERFACE
+extern void usb_midi_flush_output(void);
+#endif
+
+#ifdef FLIGHTSIM_INTERFACE
+extern void usb_flightsim_flush_callback(void);
+#endif
+
+#ifdef AUDIO_INTERFACE
+extern uint16_t usb_audio_receive_buffer[];
+extern uint16_t usb_audio_transmit_buffer[];
+extern uint32_t usb_audio_sync_feedback;
+extern uint8_t usb_audio_receive_setting;
+extern uint8_t usb_audio_transmit_setting;
+extern void usb_audio_receive_callback(unsigned int len);
+extern unsigned int usb_audio_transmit_callback(void);
+extern int usb_audio_get_feature(void *stp, uint8_t *data, uint32_t *datalen);
+extern int usb_audio_set_feature(void *stp, uint8_t *buf);
+#endif
+
+#ifdef MULTITOUCH_INTERFACE
+extern void usb_touchscreen_update_callback(void);
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#else // F_CPU < 20000000
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void usb_init(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif // F_CPU
+
+#endif