In an overall effort to privatize access to virNodeDeviceObj and
virNodeDeviceObjList into the virnodedeviceobj module, move the
object list parsing from node_device_driver and replace with a
call to a virnodedeviceobj helper. This follows other similar
APIs/helpers which peruse the object list looking for some specific
data in order to get/return an @device (virNodeDevice) object to
the caller.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>