Merge branch 'bootloader-cmsis-fix'

bootloaders/mkr1000/samd21_sam_ba_arduino_mkr1000.bin

bootloaders/mkr1000/samd21_sam_ba_arduino_mkr1000.hex

bootloaders/mkr1000/samd21_sam_ba_genuino_mkr1000.bin

bootloaders/mkr1000/samd21_sam_ba_genuino_mkr1000.hex

bootloaders/mkrzero/samd21_sam_ba_arduino_mkrzero.bin

bootloaders/mkrzero/samd21_sam_ba_arduino_mkrzero.hex

bootloaders/zero/Makefile

bootloaders/zero/board_driver_usb.c

bootloaders/zero/sam_ba_cdc.c

bootloaders/zero/sam_ba_usb.c

bootloaders/zero/samd21_sam_ba.bin

bootloaders/zero/samd21_sam_ba.hex

bootloaders/zero/samd21_sam_ba_genuino.bin

bootloaders/zero/samd21_sam_ba_genuino.hex

cores/arduino/USB/SAMD21_USBDevice.h