[PATCH] ipw2200: Add IEEE80211_RADIOTAP_TSFT for promiscuous mode

The ipw2200 BSS firmware passes on the TSF information within ipw_rx_frame,
but monitor firmware doesn't. I add back the IEEE80211_RADIOTAP_TSFT flags
so that we can get the MAC timestamp if we use the rtap interface. We will
see the MAC timestamp equals to zero if we capture the packets with a
monitor mode interface. But this is the expected behaviour.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>