RFC: sensor authors should take maintainership/ownership

[teburd]

Introduction

Zephyr gets many sensor drivers from individuals and small company authors. Maintainership/ownership of these drivers then often falls on the sensor maintainer (@MaureenHelm) and collaborators of sensors.

Problem description

When it comes time to assign bugs, rework drivers, or update sensor APIs there's no clear answer to how this works today. It shouldn't be expected that Zephyr maintainers have every sensor for every driver in the tree. Fixing bugs and updating drivers then is problematic.

Proposed change

All new sensor drivers being added to the tree require the author to take ownership and be co-maintainers for that driver with the sensors maintainer. It's expected then that bugs or required changes to those drivers are handled by the original author if possible.