Don't set the CCR_OPTION register when registering/deregistering
interrupts unless the card is a MFC card. This makes a lot of cards
work that didn't work before. These bits are only defined for MFC
cards.
Remove COOKIE_FOR_WARNER kludges that phk introduced.
Add more debug info.
Annoy the purists by committing two minor style nits at the same time.
Many thanks to phk. He tracked this problem down to what was screwing
things up, so fixing it became trivially easy once the problem was
understood.
4ee27e3969