Matrix transpose macro in serpent-sse2 uses mix of SSE2 integer and SSE floating
point instructions, which might cause performance penality on some CPUs.

This patch replaces transpose_4x4 macro with version that uses only SSE2
integer instructions.
Signed-off-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>