mac80211: process and save VHT MU-MIMO group frame

The Group ID Management frame is an Action frame of
category VHT. It is transmitted by the AP to assign
or change the user position of a STA for one or more
group IDs.
Process and save the group membership data. Notify
underlying driver of changes.

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 3943d4b..f4b2c04 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1928,6 +1928,9 @@
 			  BSS_CHANGED_IDLE |
 			  BSS_CHANGED_TXPOWER;
 
+		if (sdata->flags & IEEE80211_SDATA_MU_MIMO_OWNER)
+			changed |= BSS_CHANGED_MU_GROUPS;
+
 		switch (sdata->vif.type) {
 		case NL80211_IFTYPE_STATION:
 			changed |= BSS_CHANGED_ASSOC |