perf tools: Add long time reviewers to MAINTAINERS

Jiri and Namhyung have long contributed a lot of code and time reviewing
patches to tools/, so lets make that reflected in the MAINTAINERS file
to encourage patch submitters to add them to the CC list, speeding up
the process of tools/perf/ patch processing.

Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-onicopw68bg6kn56lnybfpns@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

MAINTAINERS

@@ -10559,6 +10559,8 @@ M:	Peter Zijlstra <peterz@infradead.org>
 M:	Ingo Molnar <mingo@redhat.com>
 M:	Arnaldo Carvalho de Melo <acme@kernel.org>
 R:	Alexander Shishkin <alexander.shishkin@linux.intel.com>
+R:	Jiri Olsa <jolsa@redhat.com>
+R:	Namhyung Kim <namhyung@kernel.org>
 L:	linux-kernel@vger.kernel.org
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/core
 S:	Supported