o Make pccard work at all by including card.h

o Make pccard work at all by including card.h
o fix return type of sio_pccard_detach
o don't free softc in deatch, since that is done by newbus
o disconnect interrupt we used to have.  Add cookie to com so that we can
  tear down the interrupt on unload
o Set gone earlier, but likely doesn't matter

This makes sio pccards work again.  Cards that are active when ejects may
not work (but they might, softc goes away quickly).

These changes are unreviewed by bde.  I'll make any style changes he wants.