sky2: only disable 88e8056 on some boards

Use DMI to add a blacklist of broken boards (so far only one).
Hopefully, the problems will be solved later, and the the whole
blacklist can disappear.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>