perf_counter: add/update copyrights

Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/perf_counter.c

 /*
  * Performance counter x86 architecture code
  *
- *  Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de>
- *  Copyright(C) 2008 Red Hat, Inc., Ingo Molnar
- *  Copyright(C) 2009 Jaswinder Singh Rajput
- *  Copyright(C) 2009 Advanced Micro Devices, Inc., Robert Richter
+ *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
+ *  Copyright (C) 2009 Jaswinder Singh Rajput
+ *  Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
  *  For licencing details see kernel-base/COPYING
  */

kernel/perf_counter.c

 /*
  * Performance counter core code
  *
- *  Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de>
- *  Copyright(C) 2008 Red Hat, Inc., Ingo Molnar
- *
+ *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
+ *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
  *  For licensing details see kernel-base/COPYING
  */