crypto: x86/blowfish - drop CTR mode implementation

Blowfish in counter mode is never used in the kernel, so there
is no point in keeping an accelerated implementation around.

Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>