MdePkg: Add the missing spec version information for header files

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: shenglei <shenglei.zhang@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

MdePkg/Include/Protocol/RegularExpressionProtocol.h

@@ -2,7 +2,7 @@
   This section defines the Regular Expression Protocol. This protocol isused to match
   Unicode strings against Regular Expression patterns.
 
-Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2015-2018, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials are licensed and made available under
 the terms and conditions of the BSD License that accompanies this distribution.
 The full text of the license may be found at
@@ -11,6 +11,9 @@ http://opensource.org/licenses/bsd-license.php.
 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
+  @par Revision Reference:
+  This Protocol was introduced in UEFI Specification 2.5.
+
 **/
 
 #ifndef __REGULAR_EXPRESSION_PROTOCOL_H__