perf_counter: add MAINTAINERS entry

This adds an entry in MAINTAINERS for the perf_counter subsystem.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <18909.13033.345975.434902@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

MAINTAINERS

@@ -3483,6 +3483,16 @@ M:	balbir@linux.vnet.ibm.com
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 
+PERFORMANCE COUNTER SUBSYSTEM
+P:	Peter Zijlstra
+M:	a.p.zijlstra@chello.nl
+P:	Paul Mackerras
+M:	paulus@samba.org
+P:	Ingo Molnar
+M:	mingo@elte.hu
+L:	linux-kernel@vger.kernel.org
+S:	Supported
+
 PERSONALITY HANDLING
 P:	Christoph Hellwig
 M:	hch@infradead.org