to check the status property in their probe routines.
Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.
Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
Freescale SoCs including the i.MX series. This also works for the newer
SoCs with the ENET gigabit controller, but doesn't use any of the new
hardware features other than enabling gigabit speed.
