mac80211: move MU_MIMO_OWNER flag to ieee80211_vif

Drivers may need to track which vif is using VHT MU-MIMO.
Move the flag indicationg the ownership of MU_MIMO to
ieee80211_vif.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index f1e5b76..89f7179 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1928,7 +1928,7 @@
 			  BSS_CHANGED_IDLE |
 			  BSS_CHANGED_TXPOWER;
 
-		if (sdata->flags & IEEE80211_SDATA_MU_MIMO_OWNER)
+		if (sdata->vif.mu_mimo_owner)
 			changed |= BSS_CHANGED_MU_GROUPS;
 
 		switch (sdata->vif.type) {