UefiCpuPkg/RegisterCpuFeaturesLib: Add "Test Then Write" Macros.

UefiCpuPkg/RegisterCpuFeaturesLib: Add "Test Then Write" Macros.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2040

Add below new micros which test the current value before write the new
value. Only write new value when current value not same as new value.
  CPU_REGISTER_TABLE_TEST_THEN_WRITE32
  CPU_REGISTER_TABLE_TEST_THEN_WRITE64
  CPU_REGISTER_TABLE_TEST_THEN_WRITE_FIELD

Also add below API:
  CpuRegisterTableTestThenWrite

Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>