fxp(4) still has timeout issues in -current

[Dustin Marquess <dmarquess%gmail.com@localhost>]

My CS20 running GENERIC.MP on a fresh copy of -current just got bit by
the old fxp(4) bug again:

fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: device timeout

I'm not sure what triggered it, but nothing short of a reboot fixed
it.  I tried ssh'ing in on fxp0 and bouncing fxp1 (ifconfig down /
ifconfig up), but that didn't have any affect.  I know this has
cropped up over the years.  Not sure if it's MP that's tickling this
or not.

Should I open a PR, or is this a known issue?

-Dustin