crypto: cavium/nitrox - updated debugfs information.

Updated debugfs to provide device partname and frequency etc.
New file "stats" shows the number of requests posted, dropped and
completed.

Signed-off-by: Srikanth Jampala <Jampala.Srikanth@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>