Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

Add a stub AR93xx RF module just to keep the linker happy.

When building AR933x test images, I'd like to only build only the ar9300
HAL. To do this, it needs to supply an RF linker entry or it won't compile.

Tested:

* AR933x test builds

The AR9300 HAL uses this config to program AR_PHY_SWITCH_COM_2 on AR9485
NICs which have bluetooth coexistence enabled.

The WB225 NIC has the common antenna switch configuration set to 0x0 which
disables all external switch bit setting. This obviously won't work when
doing coexistence.

This value is a magic value from the windows .inf files. It _looks_ right
but I haven't yet verified it - unfortunately my AR9285+AR3012 BT combo
has an earlier BT device which doesn't actually _have_ firmware on it.
So I have to fix ath3kfw to handle loading in firmware into the newer
NICs before I can finish testing this.

This may not hold true for CUS198, which is another custom AR9485 board.

Add bluetooth setup method functions to the HAL.

Tie in the LNA diversity configuration functions into the HAL.

Bring over my FreeBSD modifications for the AR9300 HAL to make it
work in FreeBSD.

This is still heavily a work in progress but I'd rather it start
shipping in -HEAD sooner rather than later.

This doesn't (yet) link it into the build system either for a static
kernel or as a module; that will come later (after many, many make universe
tests.)