Add new API GetTimeInNanoSecond() to TimerLib to convert elapsed ticks to time in unit of nanoseconds.

Signed-off-by: xdu2
Reviewed-by: mdkinney

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12206 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Include/Library/TimerLib.h

@@ -1,7 +1,7 @@
 /** @file
   Provides calibrated delay and performance counter services.
 
-Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -94,4 +94,21 @@ GetPerformanceCounterProperties (
   OUT      UINT64                    *EndValue     OPTIONAL
   );
 
+/**
+  Converts elapsed ticks of performance counter to time in nanoseconds.
+
+  This function converts the elapsed ticks of running performance counter to
+  time value in unit of nanoseconds.
+
+  @param  Ticks     The number of elapsed ticks of running performance counter.
+
+  @return The elapsed time in nanoseconds.
+
+**/
+UINT64
+EFIAPI
+GetTimeInNanoSecond (
+  IN      UINT64                     Ticks
+  );
+
 #endif