* Add Corne and Ferris shared layouts, and update the respective
shields to use them.
* Add a sample Hummingbird physical layout for testing posix xiao.
* Add Sofle physical layout as an additional reference.
* To avoid spurious CDC ACM instances when usint CDC ACM for something
other than logging, move to the approach used by Zephyr of using a
snippet to redirect console output to a CDC ACM node added by the
snippet. Remove all the existing static CDC ACM nodes.
* Add new `zmk-usb-logging` snippet that mirrors the upstream
`cdc-acm-logging` snippet, but still does our extra USB logging
configuration.
* Updated logging docs accordingly.
Co-authored-by: Cem Aksoylar <caksoylar@users.noreply.github.com>
Removed "label" properties which no longer have any function.
Labels are still used as layer names and as identifiers for sending
behaviors between sides of a split keyboard, so those have been left
alone for now.
* 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.
