Comment out sbp driver from GENERIC

[Alberto Villa]

Hello!

It has been reported several times that some motherboards have issues
at boot with sbp driver loaded. To hide the problem, the driver was
removed from GENERIC in 8-STABLE, but it was left in -CURRENT and it
is now going into 9-STABLE. Please, apply the workaround to 9-STABLE
also!

http://svnweb.freebsd.org/base?view=revision&revision=199112
-- 
Alberto Villa, FreeBSD committer <avilla at FreeBSD.org>
http://people.FreeBSD.org/~avilla