crypto: vmac - Fix big-endian support

This patch is to fix the vmac algorithm, add more test cases for vmac,
and fix the test failure on some big endian system like s390.

Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --cc crypto/testmgr.h
Simple merge

diff --cc crypto/vmac.c
Simple merge