Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Make sure the extended regdomain word is initialised.

As with the AR9285, the AR9287 has a default word of 0x1F which means
all the various bits in that field are set on by default.

Import initial EEPROM code for Kite (AR9287).

I've tested this locally and it does indeed read and attach to an AR9287
EEPROM. But a lot more code needs to be ported over to the HAL before
the AR9287 is functional.

I'm importing this separate from the rest of the codebase (and unlinked from
the build for now) in case someone wishes to begin fiddling with porting
the rest of the code over from Linux ath9k.

Obtained from: Linux ath9k