crypto: cavium - Add the Virtual Function driver for CPT

Enable the CPT VF driver. CPT is the cryptographic Acceleration Unit
in Octeon-tx series of processors.

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>