PM: runtime: Define pm_runtime_put cleanup helper

Define a cleanup helper for use with __free to automatically drop the
device usage count when the pointer goes out of scope.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://patch.msgid.link/20250422230534.2295291-2-alex.williamson@redhat.com