Add Odroid board selection

[GeoffClements]

Description

This change provides a new dialog under system that will update or append board_name=<xu4, xu3, xu3l, hc1> to /boot/armbianEnv.txt. It will also change the BOARD_NAME value in /etc/armbian-release.

The option to do this will appear only if the board family is odroidxu4.

The returns some functionality that was lost in the upgrade to armbian-configng.

Issue reference: None.
Related documentation: None

Implementation Details

• Key changes introduced by this PR
  A new entry in config.system.json and a new file under tools/modules/system.

• Justification for the changes
  Returns lost functionality

• Confirmation that no new external dependencies or modules have been introduced
  Confirmed

Documentation Summary

• [*] Metadata Included:
  Did you include the metadata (associative arrays) in the code? Ensure that metadata for modules, jobs, and runtime has been updated appropriately.
  The metadata is included, but I'm not sure I got this completely right.

• Document Generated:
  Did you generate the updated documentation using armbian-configng --doc? Confirm if the command was run to update README.md and provide any relevant details.
  There are no documentation changes.

Testing Procedure

Manually tested, conditions tested were:

• Correct line added when missing
• Correct line added when already present
• Ok and Cancel actions

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have ensured that my changes do not introduce new warnings or errors
• No new external dependencies are included
• Changes have been tested and verified
• I have included necessary metadata in the code, including associative arrays

[GeoffClements]

Apologies for the commits and reverts. I didn't realise those commits would appear in the PR, consequently I reverted them.

[igorpecovnik]

No worries. I think we are good to go at my last commit. Everyone had troubles with Git-Fu, if you struggle with this, I will do it in the morning.