perf str{filter,list}: Disentangle headers

There are places where we just need a forward declaration, and others
were we need to include strlist.h and/or strfilter.h, reducing the
impact of changes in headers on the build time, do it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-zab42gbiki88y9k0csorxekb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 9aa058e..4df228a 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -7,6 +7,7 @@
 #include "symbol.h"
 #include "evsel.h"
 #include "evlist.h"
+#include "strlist.h"
 #include <traceevent/event-parse.h>
 #include "mem-events.h"
 #include <linux/kernel.h>