x86: autoload microcode driver on Intel and AMD systems v2

Don't try to describe the actual models for now.

v2: Fix typo: X86_VENDOR_ANY -> X86_FAMILY_ANY (trenn)

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>