tools: Remove bitops/hweight usage of bits in tools/perf

We need to use lib/hweight.c for that, just like we do for lib/rbtree.c,
so tools need to link hweight.o. For now do it directly, but we need to
have a tools/lib/lk.a or .so that collects these goodies...

Reported-by: Jan Beulich <JBeulich@suse.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-a1e91dx3apzqw5kbdt7ut21s@git.kernel.org


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