Minimize the code overhead between the two TSC reads by adding new internal API to calculate TSC Frequency instead of reusing MicroSecondDelay (). Cc: Michael D Kinney <michael.d.kinney@intel.com> Cc: Liming Gao <liming.gao@intel.com> Cc: Paul A Lohr <paul.a.lohr@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Star Zeng <star.zeng@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com> Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>