add iton bt driver

[1Conan]

Adds driver for the ITON module in quite a few sonix keyboards.

Requires SonixQMK/ChibiOS-Contrib#40
Includes qmk#15947

Description

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[dexter93]

455d5fd should take care of -contrib.
qmk#16185 got merged, so better catch up with that instead of qmk#15947

[dexter93]

RIP