perf: Tidy up after the big rename

 - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's

 - provide courtesy copy of old perf_counter.h, for user-space projects

 - small indentation fixups

 - fix up MAINTAINERS

 - fix small x86 printout fallout

 - fix up small PowerPC comment fallout (use 'counter' as in register)

Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/MAINTAINERS b/MAINTAINERS
index 43761a0..751a307 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4000,7 +4000,7 @@
 F:	include/linux/delayacct.h
 F:	kernel/delayacct.c
 
-PERFORMANCE COUNTER SUBSYSTEM
+PERFORMANCE EVENTS SUBSYSTEM
 M:	Peter Zijlstra <a.p.zijlstra@chello.nl>
 M:	Paul Mackerras <paulus@samba.org>
 M:	Ingo Molnar <mingo@elte.hu>