Patch adds LRW support for twofish-x86_64-3way by using lrw_crypt(). Patch has
been tested with tcrypt and automated filesystem tests.

Tcrypt benchmarks results (twofish-3way/twofish-asm speed ratios):

Intel Celeron T1600 (fam:6, model:15, step:13):

size	lrw-enc	lrw-dec
16B	0.99x	1.00x
64B	1.17x	1.17x
256B	1.26x	1.27x
1024B	1.30x	1.31x
8192B	1.31x	1.32x

AMD Phenom II 1055T (fam:16, model:10):

size	lrw-enc	lrw-dec
16B	1.06x	1.01x
64B	1.08x	1.14x
256B	1.19x	1.20x
1024B	1.21x	1.22x
8192B	1.23x	1.24x
Signed-off-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Now that the tfm is passed directly to setkey instead of the ctx, we no
longer need to pass the &tfm->crt_flags pointer.

This patch also gets rid of a few unnecessary checks on the key length
for ciphers as the cipher layer guarantees that the key length is within
the bounds specified by the algorithm.

Rather than testing dia_setkey every time, this patch does it only once
during crypto_alloc_tfm.  The redundant check from crypto_digest_setkey
is also removed.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This patch splits up the twofish crypto routine into a common part ( key
setup  ) which will be uses by all twofish crypto modules ( generic-c , i586
assembler and x86_64 assembler ) and generic-c part. It also creates a new
header file which will be used by all 3 modules.

This eliminates all code duplication.

Correctness was verified with the tcrypt module and automated test scripts.
Signed-off-by: NJoachim Fritschi <jfritschi@freenet.de>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>