Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Don't confuse the tuple code and the tuple length. Ooops. Since most
CIS are tiny, this likely hasn't bit anybody yet...

Use the correct minor number for the pccardX.cis device.
Don't destroy a NULL device.

This should fix the panics on boot people are seeing on systems with
more than one pccard slot.

Implement /dev/pccardN.cis. This mirrors the CIS for the card to userland.

pccardc dumpcis /dev/pccardN.cis will work now, but I may rewrite pccardc.

Also, move more of the private data to a new file called pccardvarp.h.