x86: Set preferred CPU features on the KH-40000 and KX-7000 Zhaoxin processors

Fix code formatting under the Zhaoxin branch and add comments for
different Zhaoxin models.

Unaligned AVX load are slower on KH-40000 and KX-7000, so disable
the AVX_Fast_Unaligned_Load.

Enable Prefer_No_VZEROUPPER and Fast_Unaligned_Load features to
use sse2_unaligned version of memset,strcpy and strcat.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>