Add AVX2 optimized gen_syndrom functions, which is simply based on
sse2.c written by hpa.
Signed-off-by: NYuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NJim Kukunas <james.t.kukunas@linux.intel.com>
Signed-off-by: NNeilBrown <neilb@suse.de>