Removed the combined .dtsi file for each group of common layouts, and
split the position map across the files in each group. This makes
reading the position maps slightly more difficult, but it aligns the
common layouts with the keyboard-specific ones such as
foostan/corne.dtsi in that simply including each header adds the
layout, with no need to set status = "okay".
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.