crypto: cavium - Add Support for Octeon-tx CPT Engine

Enable the Physical Function driver for the Cavium Crypto Engine (CPT)
found in Octeon-tx series of SoC's. CPT is the Cryptographic Accelaration
Unit. CPT includes microcoded GigaCypher symmetric engines (SEs) and
asymmetric engines (AEs).

Signed-off-by: George Cherian <george.cherian@cavium.com>
Reviewed-by: David Daney <david.daney@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>