perf callchain: Move option parsing code to util.c

Move callchain option parse related code to util.c, to avoid dragging
more object files into the python binding.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438890294-33409-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 20d625a..8148703 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -351,4 +351,6 @@
 	return asprintf_expr_inout_ints(var, false, nints, ints);
 }
 
+int get_stack_size(const char *str, unsigned long *_size);
+
 #endif /* GIT_COMPAT_UTIL_H */