Introduce one PCD PcdCpuInitIpiDelayInMicroSeconds to specify the delay value after sending out INIT IPI instead of hard code 10 MicroSeconds.
Its default value is 10 millisecond per IA32 manual.
Platform could customize this PCD value for performance requirement.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Kinney, Michael <michael.d.kinney@intel.com>
 

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/UefiCpuPkg@15650 6f19259b-4bc3-4df7-8a09-765794883524