Added Jetson Xavier NX support

[PYBrulin]

Hi, this PR adds the detection of the Nvidia Jetson Xavier NX model (and probably the AGX-Xavier model as well since its tegra_chip_id is the same, although not tested) to the hardware detection step during the bootstrap configuration. It also adds some specific configurations useful for running Maverick on the Dev Kit.

Below is the error message occuring during bootstrap that led to this addition:

Error: Systemd start for maverick-motd failed!
journalctl log for maverick-motd:
-- Logs begin at Wed 2022-06-15 19:40:07 BST, end at Wed 2022-06-15 20:19:09 BST. --
Jun 15 20:19:05 ubuntu systemd[1]: Starting Maverick MOTD Creator...
Jun 15 20:19:09 ubuntu sh[7719]: Traceback (most recent call last):
Jun 15 20:19:09 ubuntu sh[7719]:   File "/srv/maverick/software/maverick/bin/maverick-info", line 92, in <module>
Jun 15 20:19:09 ubuntu sh[7719]:     print(twocols('Model', '\t\t\t' +tegra.data['model']))
Jun 15 20:19:09 ubuntu sh[7719]: TypeError: must be str, not NoneType
Jun 15 20:19:09 ubuntu systemd[1]: maverick-motd.service: Main process exited, code=exited, status=1/FAILURE
Jun 15 20:19:09 ubuntu systemd[1]: maverick-motd.service: Failed with result 'exit-code'.
Jun 15 20:19:09 ubuntu systemd[1]: Failed to start Maverick MOTD Creator.