x86, AMD: Extend support to future families

Extend support to future families, and in particular:

* extend direct mapping split of Tseg SMM area.
* extend K8 flavored alternatives (NOPS).
* rep movs* prefix is fast in ucode.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100602182921.GA21557@aftab>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>