device: inject device dependency information from devicetree nodes

Generate arrays of dependency information for each device.  If a
device definition is being constructed from devicetree these come from
the devicetree dependency information.  Additional dependencies may be
passed through using the DT_ macros.

Define flag values for device handles so we can partition the
dependency array into distinct sets, which include things it requires,
things it supports (may not be needed), and child nodes (not
implemented, may not be needed).

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>