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

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

Break out the iwn(4) device IDs into if_iwn_devid.h, as well as add
IDs for new devices.

* Add new device IDs
* Extend the ID probe code to include the newer range of bits used
by later model devices

Tested:

* Intel 5100, STA mode

TODO:

* Test on Intel 4965, just to be sure

Submitted by: Cedric GROSS <cg@gross.info>