Adding zubaxgnss-v1 bootloader

Images/zubaxgnss-v1.prototype

cmake/configs/nuttx_zubaxgnss-v1_bootloader.cmake

nuttx-configs/zubaxgnss-v1/Kconfig

nuttx-configs/zubaxgnss-v1/bootloader/Make.defs

nuttx-configs/zubaxgnss-v1/bootloader/README.txt

nuttx-configs/zubaxgnss-v1/bootloader/defconfig

nuttx-configs/zubaxgnss-v1/bootloader/setenv.sh

nuttx-configs/zubaxgnss-v1/include/README.txt

nuttx-configs/zubaxgnss-v1/include/board.h

nuttx-configs/zubaxgnss-v1/nsh/Make.defs

nuttx-configs/zubaxgnss-v1/nsh/defconfig

nuttx-configs/zubaxgnss-v1/nsh/setenv.sh

nuttx-configs/zubaxgnss-v1/scripts/bootloaderld.script

nuttx-configs/zubaxgnss-v1/scripts/ld.script

nuttx-configs/zubaxgnss-v1/src/Makefile

nuttx-configs/zubaxgnss-v1/src/empty.c

nuttx-configs/zubaxgnss-v1/src/ostubs.c

src/drivers/boards/zubaxgnss-v1/CMakeLists.txt

src/drivers/boards/zubaxgnss-v1/board_config.h

src/drivers/boards/zubaxgnss-v1/bootloader/CMakeLists.txt