* Only update ah_powerMode if we're setting the chip sleep state.
  Some code will appear soon that is actually setting the chip powerstate
  separate from the self-generated frames power state.
* Allow the AR5416 family chips to actually have the power state changed
  from the self generated state change.

Tested (STA mode):

* AR5210
* AR5211
* AR5412
* AR5413
* AR5416
* AR9285
Only track the power state variable if the power state is changed,
not if the self-generated frame state is changed.
Ignore writes to microcode update MSR. This MSR is accessed by RHEL7 guest.
Add KTR tracepoints to annotate wrmsr and rdmsr VM exits.
Bring over some initial power save management support, reset path
fixes and beacon programming / debugging into the ath(4) driver.

The basic power save tracking:

* Add some new code to track the current desired powersave state; and
* Add some reference count tracking so we know when the NIC is awake; then
* Add code in all the points where we're about to touch the hardware and
  push it to force-wake.

Then, how things are moved into power save:

* Only move into network-sleep during a RUN->SLEEP transition;
* Force wake the hardware up everywhere that we're about to touch
  the hardware.

The net80211 stack takes care of doing RUN<->SLEEP<->(other) state
transitions so we don't have to do it in the driver.

Next, when to wake things up:

* In short - everywhere we touch the hardware.
* The hardware will take care of staying awake if things are queued
  in the transmit queue(s); it'll then transit down to sleep if
  there's nothing left.  This way we don't have to track the
  software / hardware transmit queue(s) and keep the hardware
  awake for those.

Then, some transmit path fixes that aren't related but useful:

* Force EAPOL frames to go out at the lowest rate.  This improves
  reliability during the encryption handshake after 802.11
  negotiation.

Next, some reset path fixes!

* Fix the overlap between reset and transmit pause so we don't
  transmit frames during a reset.
* Some noisy environments will end up taking a lot longer to reset
  than normal, so extend the reset period and drop the raise the
  reset interval to be more realistic and give the hardware some
  time to finish calibration.
* Skip calibration during the reset path.  Tsk!

Then, beacon fixes in station mode!

* Add a _lot_ more debugging in the station beacon reset path.
  This is all quite fluid right now.
* Modify the STA beacon programming code to try and take
  the TU gap between desired TSF and the target TU into
  account.  (Lifted from QCA.)

Tested:

* AR5210
* AR5211
* AR5212
* AR5413
* AR5416
* AR9280
* AR9285

TODO:

* More AP, IBSS, mesh, TDMA testing
* Thorough AR9380 and later testing!
* AR9160 and AR9287 testing

Obtained from:	QCA