intel_idle: Disable Baytrail Core and Module C6 auto-demotion

Power efficiency improves on Baytrail (Intel Atom Processor E3000)
when Linux disables C6 auto-demotion.

Based on work by Srinidhi Kasagar <srinidhi.kasagar@intel.com>.

Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org