1. Add new Perf macros for performance measurement and related APIs and definitions in Performance library class. 2. Update NULL performance library instance in MdePkg. Cc: Liming Gao <liming.gao@intel.com> Cc: Michael Kinney <michael.d.kinney@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Dandan Bi <dandan.bi@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>