DTS property attributes are (by default) not required.
Explicitly specifying `required: false` is redundant.
Perhaps a warning to that effect would be useful.
Signed-off-by: Chris Friedt <cfriedt@meta.com>
Initial implementation of a simple GPIO controlled power domain.
It exposes no API of its own, all functionality is contained inside
the runtime power management callbacks.
Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>