perf bench numa: Add define for RUSAGE_THREAD if not present

While cross building perf to the ARC architecture on a fedora 30 host,
we were failing with:

      CC       /tmp/build/perf/bench/numa.o
  bench/numa.c: In function ‘worker_thread’:
  bench/numa.c:1261:12: error: ‘RUSAGE_THREAD’ undeclared (first use in this function); did you mean ‘SIGEV_THREAD’?
    getrusage(RUSAGE_THREAD, &rusage);
              ^~~~~~~~~~~~~
              SIGEV_THREAD
  bench/numa.c:1261:12: note: each undeclared identifier is reported only once for each function it appears in

[perfbuilder@60d5802468f6 perf]$ /arc_gnu_2019.03-rc1_prebuilt_uclibc_le_archs_linux_install/bin/arc-linux-gcc --version | head -1
arc-linux-gcc (ARCv2 ISA Linux uClibc toolchain 2019.03-rc1) 8.3.1 20190225
[perfbuilder@60d5802468f6 perf]$

Trying to reproduce a report by Vineet, I noticed that, with just
cross-built zlib and numactl libraries, I ended up with the above
failure.

So, since RUSAGE_THREAD is available as a define, check for that and
numactl libraries, I ended up with the above failure.

So, since RUSAGE_THREAD is available as a define in the system headers,
check if it is defined in the 'perf bench numa' sources and define it if
not.

Now it builds and I have to figure out if the problem reported by Vineet
only takes place if we have libelf or some other library available.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: https://lkml.kernel.org/n/tip-2wb4r1gir9xrevbpq7qp0amk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>