Are you using IPsec or OpenVPN?
If FreeBSD supports that crypto chip, it should be used automatically by IPsec, but there isn't a real good test for that.
For OpenVPN, you can test with and without the cryptodev settings, and also with OpenSSL at the CLI:
See here:
http://doc.pfsense.org/index.php/Are_cryptographic_accelerators_supported
If you are just seeing the "cryptosoft0" line, however, that is not an accelerator.