Consolidate creation of edtlib.EDT objects from a build directory's
devicetree into one place by loading it from build/zephyr/edt.pickle
everywhere. A previous commit creates edt.pickle from gen_defines.py.
In addition to probably speeding things up slightly by not reparsing
the devicetree, the main benefit of this approach is creating a single
point of truth for the bindings directories and warnings
configuration, meaning we don't have to worry about them getting out
of sync while being passed around between devicetree creation and
usage time.
Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
9c92baa73f