bce(4) with IPMI

[Sean Bruno]

We've been getting reports of odd behavior on our Dell R410 machines
when trying to use IPMI.  The servers have two NIC's that we have
assigned as the IPMI interface(bce0) and production interface(bce1)
respectively.

Since we don't actually configure bce0 in FreeBSD, we've found that the
IPMI interface deactivated when bce(4) loads.  I assume that the driver
is not initializing the interface correctly in this case and the default
case is to turn the interface off.  Does it make sense to completely
turn off the interface when there is an active link on the port, but no
configuration assigned?

Sean

p.s. Dell's IPMI implementation is ... um ... more difficult than it
needs to be.