Add libperf subpackage
    
    Adding libperf subpackage, that generates following rpms:
    
      # rpm -ql libperf
      /usr/lib/.build-id
      /usr/lib/.build-id/4d
      /usr/lib/.build-id/4d/a5a1484b783b31b0a4a58e0d28846fc05d947d
      /usr/lib64/libperf.so.0
      /usr/lib64/libperf.so.0.0.1
      /usr/share/licenses/libperf
      /usr/share/licenses/libperf/COPYING
    
      # rpm -ql libperf-devel
      /usr/include/perf/core.h
      /usr/include/perf/cpumap.h
      /usr/include/perf/event.h
      /usr/include/perf/evlist.h
      /usr/include/perf/evsel.h
      /usr/include/perf/mmap.h
      /usr/include/perf/threadmap.h
      /usr/lib64/libperf.a
      /usr/lib64/libperf.so
      /usr/lib64/pkgconfig/libperf.pc
      /usr/share/doc/libperf/examples/sampling.c
      /usr/share/doc/libperf/html/libperf-counting.html
      /usr/share/doc/libperf/html/libperf-sampling.html
      /usr/share/doc/libperf/html/libperf.html
      /usr/share/licenses/libperf-devel
      /usr/share/licenses/libperf-devel/COPYING
      /usr/share/man/man3/libperf.3.gz
      /usr/share/man/man7/libperf-counting.7.gz
      /usr/share/man/man7/libperf-sampling.7.gz
    
      # rpm -ql libperf-debuginfo
      /usr/lib/debug
      /usr/lib/debug/.build-id
      /usr/lib/debug/.build-id/4d
      /usr/lib/debug/.build-id/4d/a5a1484b783b31b0a4a58e0d28846fc05d947d
      /usr/lib/debug/.build-id/4d/a5a1484b783b31b0a4a58e0d28846fc05d947d.debug
      /usr/lib/debug/usr
      /usr/lib/debug/usr/lib64
      /usr/lib/debug/usr/lib64/libperf.so.0.0.1-5.6.4-400.fc32.x86_64.debug
    
    koji scratch build: https://koji.fedoraproject.org/koji/taskinfo?taskID=43395164
    
    Signed-off-by: Michael Petlan <mpetlan@redhat.com>
    Signed-off-by: Jiri Olsa <jolsa@redhat.com>