crypto: picoxcell - support for device tree matching

Allow the crypto engines to be matched from device tree bindings.

Cc: devicetree-discuss@lists.ozlabs.org
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>