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/PeiMpLib.c

@@ -1,7 +1,7 @@
 /** @file
   MP initialize support functions for PEI phase.
 
-  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
 
 **/
@@ -401,9 +401,10 @@ MpInitLibStartupAllAPs (
     return EFI_UNSUPPORTED;
   }
 
-  return StartupAllAPsWorker (
+  return StartupAllCPUsWorker (
            Procedure,
            SingleThread,
+           TRUE,
            NULL,
            TimeoutInMicroseconds,
            ProcedureArgument,