interrupt storm on MSI IXP600 based motherboards

[Pete French]

> trouble with onboard re(4) was resolved in -CURRENT and -STABLE, but 
> storms are not bound to ethernet only. storm may appear on any device. 
> if any device generates enough interrupts rate, storm will arrive.

Yes, I just got another storm, on my ATA controller this time. Ah
well, so much for the idea of disabling unneeded devices!

-pete.