wifi: mac80211: maintain link_id in link_sta

To helper drivers if they e.g. have a lookup of the link_sta
pointer, add the link ID to the link_sta structure.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -2135,6 +2135,7 @@ struct ieee80211_sta_txpwr {
  * @addr: MAC address of the Link STA. For non-MLO STA this is same as the addr
  *	in ieee80211_sta. For MLO Link STA this addr can be same or different
  *	from addr in ieee80211_sta (representing MLD STA addr)
+ * @link_id: the link ID for this link STA (0 for deflink)
  * @supp_rates: Bitmap of supported rates
  * @ht_cap: HT capabilities of this STA; restricted to our own capabilities
  * @vht_cap: VHT capabilities of this STA; restricted to our own capabilities
@@ -2151,6 +2152,7 @@ struct ieee80211_sta_txpwr {
  */
 struct ieee80211_link_sta {
 	u8 addr[ETH_ALEN];
+	u8 link_id;
 
 	u32 supp_rates[NUM_NL80211_BANDS];
 	struct ieee80211_sta_ht_cap ht_cap;

net/mac80211/sta_info.c

@@ -472,6 +472,7 @@ static void sta_info_add_link(struct sta_info *sta,
 	link_info->sta = sta;
 	link_info->link_id = link_id;
 	link_info->pub = link_sta;
+	link_sta->link_id = link_id;
 	rcu_assign_pointer(sta->link[link_id], link_info);
 	rcu_assign_pointer(sta->sta.link[link_id], link_sta);
 }