Adding McHCK DFU Bootloader

- Heavily modified, not compatible with McHCK images
- Uses 4k of Flash (rather than 3k)
- LED turns on when in firmware flash mode
- Changed the USB IDs
- Added CMake build system
- Updated linker script to be closer to what is used for the rest of the projects
- Removed a lot of unnecessary code
- Added a license header to each file (using the same license as the McHCK had)
- Updated the USB Vendor, Product and Serial strings
- Using the Kiibohd initialization sequence rather than the McHCK one
- Using Kiibohd interrupt vector table and other misc mk20dx setup

Bootloader/dfu.desc.h

@@ -0,0 +1,43 @@
+// Originally Generated from MCHCK Toolkit
+/* Copyright (c) Jacob Alexander 2014 <haata@kiibohd.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __DFU_DESC_H
+#define __DFU_DESC_H
+
+// ----- Local Includes -----
+
+#include "mchck.h"
+
+
+
+// ----- Variables -----
+
+const struct usbd_device dfu_device;
+
+usbd_init_fun_t init_usb_bootloader;
+
+
+
+// ----- Structs -----
+
+struct usb_config_1 {
+	struct usb_desc_config_t config;
+	struct dfu_function_desc usb_function_0;
+};
+
+#endif
+