qcacmn: Rectify compilation issue in MLO manager client

Rectify compilation issue in MLO manager client code by explicitly
providing a tentative bool return for mlo_is_mld_sta() which is
currently only in skeletal form.

CRs-Fixed: 2972899
Change-Id: Ia5a8b2108bc5237f9f130c6bdeca55e1c0a65f0d

umac/mlo_mgr/src/wlan_mlo_mgr_sta.c

@@ -54,4 +54,5 @@ void mlo_sta_link_down_notify(struct wlan_objmgr_vdev *vdev)
 
 bool mlo_is_mld_sta(struct wlan_objmgr_vdev *vdev)
 {
+	return false;
 }