perf tools: Introduce tools/lib/lk library

This introduces the tools/lib/lk library, that will gradually have the
routines that now are used in tools/perf/ and other tools and that can
be shared.

Start by carving out debugfs routines for general use.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1361374353-30385-5-git-send-email-bp@alien8.de
[ committer note: Add tools/lib/lk/ to perf's MANIFEST so that its tarballs continue to build ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/python-ext-sources

@@ -15,7 +15,6 @@ util/thread_map.c
 util/util.c
 util/xyarray.c
 util/cgroup.c
-util/debugfs.c
 util/rblist.c
 util/strlist.c
 util/sysfs.c