crypto: serpent-sse2 - use crypto_[un]register_algs

Combine all crypto_alg to be registered and use new crypto_[un]register_algs
functions. Simplifies init/exit code and reduce object size.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>