DTS modules (device modules) often have a single source file with an empty `struct Module`.
The module's yaml file now allows a `dts-only` boolean to be set, so the source file becomes optional.
`devicetree.yaml` is renamed everywhere to `module.yaml`
Adds sub-GHz radio support to Tactility as a first-class kernel device type, plus a
driver for the Semtech SX1262. Continues the radio work discussed in #342, brought up to
the current kernel driver model (rather than the deprecated tt::hal layer the earlier
prototype targeted).
