UefiCpuPkg/MpService: Put APs to sleep when not busy.

Add a new sleeping state for APs, when no procedure execution, put AP to sleep. when need to execute 
procedure, only need to wake up this AP by sent SIPI.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17023 6f19259b-4bc3-4df7-8a09-765794883524

UefiCpuPkg/CpuDxe/CpuMp.h

@@ -80,7 +80,8 @@ typedef enum {
   CpuStateBlocked,
   CpuStateReady,
   CpuStateBusy,
-  CpuStateFinished
+  CpuStateFinished,
+  CpuStateSleeping
 } CPU_STATE;
 
 /**