This uses the new configuration changes indicated up by
mac80211 when all interfaces are marked idle. We need to do
a little more work as we have our own set of virtual
wiphys within ath9k.

Only when all virtual wiphys are inactive do we allow an idle
state change for a wiphy to trigger disabling the radio.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>