crypto: blowfish-x86_64 - blacklist Pentium 4

Implementation in blowfish-x86_64 uses 64bit rotations which are slow on P4,
making blowfish-x86_64 slower than generic C implementation. Therefore
blacklist P4.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>