device_get_property: add a HANDLE case

This will resolve a reference and return the appropriate handle, a node
on the simplebus or an ACPI_HANDLE for ACPI. For now we do not try to
further abstract the return type.

Reviewed by: mw
Differential Revision: https://reviews.freebsd.org/D36793

(cherry picked from commit 99e6980fcf5e12654c3e89b97b774de807d740a4)