an0 turns on after suspend/resume

My Thinkpad R40 has a built-in an WiFi mini-PCI card.  I seldom use it,
so I just leave it unconfigured, which seems to leave it powered off. If
I suspend it to S3 and then resume, the broadcast antenna LED under the
display turns on, indicating that the card is active.  I also see four
messages on the console "an0: unknown RID: 0".

There are a couple of differences in the output of ancontrol -C and
ancontrol -S before and after suspend:

Before:
	Node name:                              [                 ]
	Operating mode:         [ ]

After:
	Node name:                              [ FreeBSD         ]
	Operating mode:         [ configured MAC ON RX ON ]