mac80211: don't duplicate station QoS capability data

We currently track the QoS capability twice: for all peer stations
in the WLAN_STA_WME flag, and for any clients associated to an AP
interface separately for drivers in the sta->sta.wme field.

Remove the WLAN_STA_WME flag and track the capability only in the
driver-visible field, getting rid of the limitation that the field
is only valid in AP mode.

Reviewed-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index dae2e24..1cd8444 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1405,7 +1405,7 @@
  * @supp_rates: Bitmap of supported rates (per band)
  * @ht_cap: HT capabilities of this STA; restricted to our own capabilities
  * @vht_cap: VHT capabilities of this STA; restricted to our own capabilities
- * @wme: indicates whether the STA supports WME. Only valid during AP-mode.
+ * @wme: indicates whether the STA supports QoS/WME.
  * @drv_priv: data area for driver use, will always be aligned to
  *	sizeof(void *), size is determined in hw information.
  * @uapsd_queues: bitmap of queues configured for uapsd. Only valid