MAINTAINERS: Update John Garry's email address for arm64 perf tooling

Update my address.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20221121113018.1899426-1-john.g.garry@oracle.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>