perf jvmti: Plug compilation into perf build

Compile jvmti agent as part of the perf build. The agent library is
called libperf-jvmti.so and is installed in default place together with
other files:

  $ make libperf-jvmti.so
    BUILD:   Doing 'make -j4' parallel build
    ...
    CC       jvmti/libjvmti.o
    CC       jvmti/jvmti_agent.o
    LD       jvmti/jvmti-in.o
    LINK     libperf-jvmti.so

  $ make DESTDIR=/tmp/krava/ install-bin
  ...
  $ find /tmp/krava/ | grep libperf
  /tmp/krava/lib64/libperf-jvmti.so
  /tmp/krava/lib64/libperf-gtk.so

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: William Cohen <wcohen@redhat.com>
Link: http://lkml.kernel.org/r/1478093749-5602-4-git-send-email-jolsa@kernel.org


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