UefiCpuPkg/MpInitLib: Add MpInitLibStartupAllCPUs API.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1973

Add new MpInitLibStartupAllCPUs API uses to start all processors
at the same time.

Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Chandana Kumar <chandana.c.kumar@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>

UefiCpuPkg/Library/MpInitLib/MpLib.h

@@ -1,7 +1,7 @@
 /** @file
   Common header file for MP Initialize Library.
 
-  Copyright (c) 2016 - 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2016 - 2019, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -405,6 +405,7 @@ InitMpGlobalData (
                                       number.  If FALSE, then all the enabled APs
                                       execute the function specified by Procedure
                                       simultaneously.
+  @param[in]  ExcludeBsp              Whether let BSP also trig this task.
   @param[in]  WaitEvent               The event created by the caller with CreateEvent()
                                       service.
   @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds for
@@ -426,9 +427,10 @@ InitMpGlobalData (
 
 **/
 EFI_STATUS
-StartupAllAPsWorker (
+StartupAllCPUsWorker (
   IN  EFI_AP_PROCEDURE          Procedure,
   IN  BOOLEAN                   SingleThread,
+  IN  BOOLEAN                   ExcludeBsp,
   IN  EFI_EVENT                 WaitEvent               OPTIONAL,
   IN  UINTN                     TimeoutInMicroseconds,
   IN  VOID                      *ProcedureArgument      OPTIONAL,