MdeModulePkg: Duplicate BaseRngLibTimerLib to MdeModulePkg

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4504

The BaseRngLibTimerLib allows to generate number based on a timer.
This mechanism allows to have a basic non-secure implementation
for non-production platforms.
To bind and identify Random Number Generators implementations with
a GUID, an unsafe GUID should be added. This GUID cannot be added
to the MdePkg unless it is also added to a specification.

To keep the MdePkg self-contained, copy the BaseRngLibTimerLib to
the MdeModulePkg. This will allow to define an unsafe Rng GUID
in a later patch in the MdeModulePkg.

The MdePkg implementation will be removed later. This allows to give
some time to platform owners to switch to the MdeModulePkg
implementation.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Kun Qin <kun.qin@microsoft.com>

MdeModulePkg/Library/BaseRngLibTimerLib/BaseRngLibTimerLib.inf

@@ -0,0 +1,36 @@
+## @file
+#  Instance of RNG (Random Number Generator) Library.
+#
+#  BaseRng Library that uses the TimerLib to provide reasonably random numbers.
+#  Do NOT use this on a production system as this uses the system performance
+#  counter rather than a true source of random in addition to having a weak
+#  random algorithm. This is provided primarily as a source of entropy for
+#  OpenSSL for platforms that do not have a good built in RngLib as this
+#  emulates what was done before (though it isn't perfect).
+#
+#  Copyright (c) Microsoft Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+  INF_VERSION                    = 1.27
+  BASE_NAME                      = BaseRngLibTimerLib
+  MODULE_UNI_FILE                = BaseRngLibTimerLib.uni
+  FILE_GUID                      = 74950C45-10FC-4AB5-B114-49C87C17409B
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = RngLib
+
+[Sources]
+  RngLibTimer.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  TimerLib