qcacld-3.0: Fill flexible TWT feature info in twt_feature_set

With this change - I9f8b4186753ec9d446399be9e1cfc03a63a17391
code to fill flexible TWT feature info in twt_feature_set
was removed, as a result host fails to update flexible TWT
feature to fw as part of feature set query.

To address this issue, bring back the code to fill
flexible TWT feature info in to twt_feature_set.

Change-Id: Ia669992c92a02a909d5b64925b903bdef7fc1baa
CRs-Fixed: 3594895

components/umac/twt/dispatcher/src/wlan_twt_cfg_ext_api.c

@@ -85,6 +85,7 @@ void wlan_twt_get_feature_info(struct wlan_objmgr_psoc *psoc,
 		wlan_twt_cfg_get_requestor(
 					psoc,
 					&twt_feature_set->enable_twt_requester);
+		twt_feature_set->enable_twt_flexible = true;
 	}
 }
 #endif