Previously, we would store the operating mode at interface up time,
but only update the PCU registers when the next reset happened.
The result is that if beacon configuration (ops->bss_info_changed)
happens before ops->config, we will program the wrong things into
the timer registers.  Consequently, beacons won't work in AP mode
until after a reset (channel change, scan etc.).

This is fragile anyway so just program the opmode as soon as
mac80211 gives it to us.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>