UefiCpuPkg: Adding a new TSC library by using CPUID(0x15) TSC leaf

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1909

Cc: Ray Ni <ray.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Amy Chan <amy.chan@intel.com>
Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Signed-off-by: Donald Kuo <donald.kuo@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>

UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c

@@ -0,0 +1,41 @@
+/** @file
+  CPUID Leaf 0x15 for Core Crystal Clock frequency instance as Base Timer Library.
+
+  Copyright (c) 2019 Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Library/TimerLib.h>
+#include <Library/BaseLib.h>
+
+/**
+  CPUID Leaf 0x15 for Core Crystal Clock Frequency.
+
+  The TSC counting frequency is determined by using CPUID leaf 0x15. Frequency in MHz = Core XTAL frequency * EBX/EAX.
+  In newer flavors of the CPU, core xtal frequency is returned in ECX or 0 if not supported.
+  @return The number of TSC counts per second.
+
+**/
+UINT64
+CpuidCoreClockCalculateTscFrequency (
+  VOID
+  );
+
+/**
+  Internal function to retrieves the 64-bit frequency in Hz.
+
+  Internal function to retrieves the 64-bit frequency in Hz.
+
+  @return The frequency in Hz.
+
+**/
+UINT64
+InternalGetPerformanceCounterFrequency (
+  VOID
+  )
+{
+  return CpuidCoreClockCalculateTscFrequency ();
+}
+