OvmfPkg: clone SmmCpuPlatformHookLib from UefiCpuPkg

Clone the Null instance of SmmCpuPlatformHookLib from UefiCpuPkg to
OvmfPkg. In this patch, customize the lib instance only with the following
no-op steps:

- Replace Null/NULL references in filenames and comments with Qemu/QEMU
  references.
- Update copyright notices.
- Clean up and rewrap comment blocks.
- Update INF_VERSION to the latest INF spec version (1.29).
- Update FILE_GUID.
- Drop the UNI file.

This patch is best reviewed with:

$ git show --find-copies=43 --find-copies-harder

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1512
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200226221156.29589-4-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

OvmfPkg/Library/SmmCpuPlatformHookLibQemu/SmmCpuPlatformHookLibQemu.inf

@@ -0,0 +1,29 @@
+## @file
+#  SMM CPU Platform Hook library instance for QEMU.
+#
+#  Copyright (c) 2020, Red Hat, Inc.
+#  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION                    = 1.29
+  BASE_NAME                      = SmmCpuPlatformHookLibQemu
+  FILE_GUID                      = 154D6D26-54B8-45BC-BA3A-CBAA20C02A6A
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = SmmCpuPlatformHookLib
+
+#
+# The following information is for reference only and not required by the build
+# tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  SmmCpuPlatformHookLibQemu.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec