x86: Tighten dependencies of CPU_SUP_*_32

Building in support for either of these CPUs is pointless when
e.g. M686 was selected (since such a kernel would use cmov
instructions, which aren't available on these older CPUs).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/4F58875A02000078000770E0@nat28.tlf.novell.com


Signed-off-by: Ingo Molnar <mingo@elte.hu>