crypto: Add hash param to pkcs1pad

This adds hash param to pkcs1pad.
The pkcs1pad template can work with or without the hash.
When hash param is provided then the verify operation will
also verify the output against the known digest.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>