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.uni

@@ -0,0 +1,15 @@
+// @file
+// Instance of RNG (Random Number Generator) Library.
+//
+// RngLib that uses TimerLib's performance counter to provide random numbers.
+//
+// Copyright (c) Microsoft Corporation.
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+
+
+#string STR_MODULE_ABSTRACT     #language en-US "Instance of RNG Library"
+
+#string STR_MODULE_DESCRIPTION  #language en-US "BaseRng Library that uses the TimerLib to provide low-entropy random numbers"
+