feat(boards): Update for mikoto board definition

[zhiayang]

This PR updates the mikoto board definition to use Zephyr revisions, while adding support for new revisions (6.1+, 7.1+) that have incompatibilities/new hardware.

I only version mikoto with MAJOR.MINOR, so I've set the PATCH level to 0 for the zephyr overlay files. Unfortunately this breaks existing configs that use mikoto_520 as the board name. Is that a major issue?

Board/Shield Check-list

• This board/shield is tested working on real hardware
• Definitions follow the general style of other shields/boards upstream (Reference)
• .zmk.yml metadata file added
• Proper Copyright + License headers added to applicable files (Generally, we stick to "The ZMK Contributors" for copyrights to help avoid churn when files get edited)
• General consistent formatting of DeviceTree files
• Kconfig.defconfig file correctly wraps all configuration in conditional on the shield symbol
• .conf file has optional extra features commented out
• Keyboard/PCB is part of a shipped group buy or is generally available in stock to purchase (OSH/personal projects without general availability should create a zmk-config repo instead)

[zhiayang]

a bunch of stuff came up, haven't had time to move this forward atm. though i will say that my changes work locally (ignoring any breaking changes).

[zhiayang]

had some time to pick this up again; so what i've changed now is:

1. teach the schema about the new fields revisions and default_revision. in case you're curious about the regex, it comes from the zephyr docs; it handles LETTER, NUMBER, and MAJOR.MINOR.PATCH revisions.
2. put back mikoto_520; it can still be used as in -DBOARD=mikoto_520, and i've tried my best to deduplicate the definitions and stuff.
3. edit the setup script (only the bash one for now -- if this approach is OK-ed i'll update the powershell one too) to teach it about board revisions. Mikoto 5.20 is still in there, but i've marked it deprecated -- and the zmk metadata makes it alias [email protected].

basically, now we should handle the new cases (board@revision) for all boards that opt-in to this mechanism, and we keep compat with people using mikoto_520 in their repos.

EDIT: I've split out the non-mikoto stuff into a new PR #2157, which should be merged first. I'll rebase this on that after.

I've set up a test repo that builds both mikoto_520 and [email protected], and both work: https://github.com/zhiayang/zmk-test

[caksoylar]

I think this commit efa9134 included these three files (build.sh, uf2s) by accident.

[zhiayang]

oops, you're right. I'll clean this up after #2157 gets merged, thanks!

[zhiayang]

aight, #2157 got merged so i'll pick this up in a bit