intel_idle: Rename cpuidle states

Userspace apps might have to cut off parts off the
idle state name for display reasons.
Switch NHM-C1 to C1-NHM (and others) so that a cut off
name is unique and makes sense to the user.

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: lenb@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>