arm: perf: factor arm_pmu core out to drivers

To enable sharing of the arm_pmu code with arm64, this patch factors it
out to drivers/perf/. A new drivers/perf directory is added for
performance monitor drivers to live under.

MAINTAINERS is updated accordingly. Files added previously without a
corresponsing MAINTAINERS update (perf_regs.c, perf_callchain.c, and
perf_event.h) are also added.

Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: augmented Kconfig help slightly]
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index fd60784..485c92c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -799,11 +799,13 @@
 ARM PMU PROFILING AND DEBUGGING
 M:	Will Deacon <will.deacon@arm.com>
 S:	Maintained
-F:	arch/arm/kernel/perf_event*
+F:	arch/arm/kernel/perf_*
 F:	arch/arm/oprofile/common.c
-F:	arch/arm/include/asm/pmu.h
 F:	arch/arm/kernel/hw_breakpoint.c
 F:	arch/arm/include/asm/hw_breakpoint.h
+F:	arch/arm/include/asm/perf_event.h
+F:	drivers/perf/arm_pmu.c
+F:	include/linux/perf/arm_pmu.h
 
 ARM PORT
 M:	Russell King <linux@arm.linux.org.uk>