MAINTAINERS: Add James Clark as a perf tools reviewer

James Clark has been actively reviewing patches and contributing
to perf tools. Reflect this by adding him as a reviewer in the
MAINTAINERS file.

Reviewed-by: James Clark <james.clark@linaro.org>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Author: acmel

MAINTAINERS

@@ -20157,6 +20157,7 @@ R:	Alexander Shishkin <alexander.shishkin@linux.intel.com>
 R:	Jiri Olsa <jolsa@kernel.org>
 R:	Ian Rogers <irogers@google.com>
 R:	Adrian Hunter <adrian.hunter@intel.com>
+R:	James Clark <james.clark@linaro.org>
 L:	linux-perf-users@vger.kernel.org
 L:	linux-kernel@vger.kernel.org
 S:	Supported