Add ability to flash firmware from Seeed on a Jetson board #39

Currently the script only supports flashing firmware directly from Nvidia. It would be nice to also support installing Seeed firmware for times when their carrier boards are used.

The instructions can be found here. Note that they might differ between Jetpack versions: https://wiki.seeedstudio.com/reComputer_J4012_Flash_Jetpack/#flash-jetpack