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