Initial porting of MKRLoRa1300

boards.txt

...loaders/mkrlora1300/samd21_sam_ba_arduino_mkrlora1300.bin

...loaders/mkrlora1300/samd21_sam_ba_arduino_mkrlora1300.hex

bootloaders/zero/board_definitions.h

bootloaders/zero/board_definitions_arduino_mkrlora1300.h

bootloaders/zero/build_all_bootloaders.sh

variants/mkrlora1300/debug_scripts/variant.gdb

...s/mkrlora1300/linker_scripts/gcc/flash_with_bootloader.ld

...krlora1300/linker_scripts/gcc/flash_without_bootloader.ld

variants/mkrlora1300/openocd_scripts/arduino_zero.cfg

variants/mkrlora1300/pins_arduino.h

variants/mkrlora1300/variant.cpp

variants/mkrlora1300/variant.h