Don't check the auth algorithm for GCM.

[jhb]

Summary

The upstream OpenSSL changes only set the cipher for GCM since the
authentication is redundant, and changes to OCF will soon remove
the GCM authentication algorithm constants entirely for the same
reason. In addition, ktls_create_session() already validates these
fields and wouldn't pass down an invalid auth_algorithm value to
any drivers or ktls backends.