fastboot: add flashing bootloader commands

add the following commands:
    flashing unlock_bootloader
    flashing lock_bootloader
    flashing get_unlock_bootloader_nonce

Change-Id: Ia4f56ebdcb6785a5196cc669d68da1553ed53c58
Signed-off-by: Patrick Tjin <pattjin@google.com>
1 file changed