crypto: nx - merge nx-compress and nx-compress-crypto

Merge the nx-842.c code into nx-842-crypto.c.

This allows later patches to remove the 'platform' driver, and instead
allow each platform driver to directly register with the crypto
compression api.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>