UefiCpuPkg/MicrocodeFlashAccessLib: Add NULL MicrocodeFlashAccessLib.

Add NULL instance to pass build.

Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Chao Zhang <chao.b.zhang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>

UefiCpuPkg/Feature/Capsule/Library/MicrocodeFlashAccessLibNull/MicrocodeFlashAccessLibNull.inf

@@ -0,0 +1,40 @@
+## @file
+#  Microcode flash device access library.
+#
+#  Microcode flash device access library NULL instance.
+#
+#  Copyright (c) 2016, 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
+#  which accompanies this distribution.  The full text of the license may be found at
+#  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.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = MicrocodeFlashAccessLibNull
+  MODULE_UNI_FILE                = MicrocodeFlashAccessLibNull.uni
+  FILE_GUID                      = 6F871ADD-9D86-4676-8BAD-68E2E451FC5B
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = MicrocodeFlashAccessLib
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64 IPF EBC
+#
+
+[Sources]
+  MicrocodeFlashAccessLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec
+
+[LibraryClasses]
+  BaseMemoryLib