MAINTAINERS: Add git information for perf-tools and perf-tools-next trees/branches

MAINTAINERS: Add git information for perf-tools and perf-tools-next trees/branches

Now the perf tools development is done on these trees/branches:

  git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools.git perf-tools
  git git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git perf-tools-next

For a while I'll continue mirroring what is these to the same branches
in my git tree.

Suggested-by: John Garry <john.g.garry@oracle.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/CAP-5=fVGOP6-k=BTRd_bn=N0HVy+1ShpdW5rk5ND0ZGhm_fQkg@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>