* Move away from DT_LABEL.
* Move to DEVICE_DT_GET for non-behavior device access.
* Move various drivers to `gpio_spec_dt` and `DT` related macros.
* Remove mcp23017 while at it, since better upstream driver is
available.
* Update docs for mod-morph
* Add unit tests for mod-morph
* Add keep-mods to DT binding
Co-authored-by: Martin Aumüller <aumuell@reserv.at>
Co-authored-by: Cem Aksoylar <caksoylar@users.noreply.github.com>