[PATCH] x86-64: x86_64 rename X86_FEATURE_DTES to X86_FEATURE_DS

Here is a patch (used by perfmon2) that renamed X86_FEATURE_DTES
to X86_FEATURE_DS to match Intel's documentation for the Debug Store
save area. The patch also adds cpu_has_ds.

changelog:
	- rename X86_FEATURE_DTES to X86_FEATURE_DS to match documentation
	- adds cpu_has_ds to test for X86_FEATURE_DS

Signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Andi Kleen <ak@suse.de>