ACPI: PAD: mark Zhaoxin CPUs NONSTOP TSC correctly

Zhaoxin CPUs support NONSTOP TSC feature, so do not mark these CPUs
TSC unstable when use the acpi_pad driver.

Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>