FmpDevicePkg: Add FmpDependencyCheck library class and instances

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2696

* This library class provides platform specific services to support
dependency check during updating firmware image. Platform can perform
dependency check in platform specific manner by implementing its own
FmpDependencyCheckLib.
* Add FmpDependencyCheck instance to provide a sample of dependency
check. The sample instance only checks the dependency from capsule
image. The dependency from other FMP instances isn't checked here.
* Add NULL instance as an option to skip the dependency check.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Signed-off-by: Wei6 Xu <wei6.xu@intel.com>
Reviewed-by: Sean Brogan <sean.brogan@microsoft.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

FmpDevicePkg/Library/FmpDependencyCheckLibNull/FmpDependencyCheckLibNull.inf

@@ -0,0 +1,30 @@
+## @file
+#  Null instance of FmpDependencyCheckLib as an option to skip the dependency
+#  check when updating the firmware image of a FMP device.
+#
+#  Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION     = 0x00010005
+  BASE_NAME       = FmpDependencyCheckLibNull
+  MODULE_UNI_FILE = FmpDependencyCheckLibNull.uni
+  FILE_GUID       = D63F3166-9CBC-4AC2-8F23-8818E42EA2BD
+  MODULE_TYPE     = DXE_DRIVER
+  VERSION_STRING  = 1.0
+  LIBRARY_CLASS   = FmpDependencyCheckLib|DXE_DRIVER UEFI_DRIVER UEFI_APPLICATION
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64 ARM AARCH64
+#
+
+[Sources]
+  FmpDependencyCheckLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  FmpDevicePkg/FmpDevicePkg.dec