esp_wifi: Fix some wifi bugs.

1. Send encrypted mgmt frames in pmf connection
2. Remove dependecy of SHA256 AKM on PMF
3. Fix null pointer dereference
4. Set TTLS default phase2 method as MSCHAPV2.

components/esp_wifi/lib

@@ -1 +1 @@
-Subproject commit c69597c79fc5d3b2bffb5cc330bd7ab8f956e460
+Subproject commit d530c227d7cd073ce14658124325e0352fae4e1d

components/wpa_supplicant/src/crypto/tls_mbedtls.c

@@ -502,6 +502,10 @@ struct tls_connection * tls_connection_init(void *tls_ctx)
 
 void tls_connection_deinit(void *tls_ctx, struct tls_connection *conn)
 {
+	/* case: tls init failed */
+	if (!conn) {
+		return;
+	}
 	/* Free ssl ctx and data */
 	tls_mbedtls_conn_delete((tls_context_t *) conn->tls);
 	os_free(conn->tls);

components/wpa_supplicant/src/eap_peer/eap.c

@@ -476,8 +476,11 @@ int eap_peer_config_init(
 			  sm->config.new_password_len);
 	}
 
-    if (g_wpa_ttls_phase2_type) {
-        sm->config.phase2 = g_wpa_ttls_phase2_type;
+	if (g_wpa_ttls_phase2_type) {
+		sm->config.phase2 = g_wpa_ttls_phase2_type;
+	} else {
+		/* set default config phase2 mode as MSCHAPV2 */
+		sm->config.phase2 = "auth=MSCHAPV2";
 	}
 
 	return 0;