LinuxKPI: add device_reprobe() and device_release_driver()

Add two new (though untested) functions to linux/device.h which are
dealing with manually managing the device/driver and are used by
at least one wireless driver. We may have to re-fine them in the
future.
Move the devres declarations further up so they can be used earlier
in the file.

Sponsored by: The FreeBSD Foundation
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D30519

(cherry picked from commit 644b4f117634e3b571031026be87429bea0c30dd)