MAINTAINERS: Add Mailing list and Web-page for PERFORMANCE EVENTS SUBSYSTEM

Add entry "L: [e-mail]" to archive the
related mail on https://lore.kernel.org/linux-perf-users/, add
entry "W: https://perf.wiki.kernel.org/" so that newbies could
get some useful materials.

Signed-off-by: Tiezhu Yang <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lore.kernel.org/lkml/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

MAINTAINERS

···
 R:	Alexander Shishkin <[e-mail]>
 R:	Jiri Olsa <[e-mail]>
 R:	Namhyung Kim <[e-mail]>
+L:	[e-mail]
 L:	[e-mail]
 S:	Supported
+W:	https://perf.wiki.kernel.org/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/core
 F:	arch/*/events/*
 F:	arch/*/events/*/*