Add install targets (mostly copied from tools/lib/bpf), it's now
possible to install libperf with:

  $ make DESTDIR=/tmp/krava  install
    INSTALL  libperf.a
    INSTALL  libperf.so
    INSTALL  libperf.so.0
    INSTALL  libperf.so.0.0.1
    INSTALL  headers
    INSTALL  libperf.pc

  $ find /tmp/krava/
  /tmp/krava/
  /tmp/krava/include
  /tmp/krava/include/perf
  /tmp/krava/include/perf/evsel.h
  /tmp/krava/include/perf/evlist.h
  /tmp/krava/include/perf/threadmap.h
  /tmp/krava/include/perf/cpumap.h
  /tmp/krava/include/perf/core.h
  /tmp/krava/lib64
  /tmp/krava/lib64/pkgconfig
  /tmp/krava/lib64/pkgconfig/libperf.pc
  /tmp/krava/lib64/libperf.so.0.0.1
  /tmp/krava/lib64/libperf.so.0
  /tmp/krava/lib64/libperf.so
  /tmp/krava/lib64/libperf.a

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190721112506.12306-72-jolsa@kernel.org


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