perf tools: Factorize the map helpers

Factorize the dso mapping helpers into a single purpose common file
"util/map.c"

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Brice Goglin <Brice.Goglin@inria.fr>

tools/perf/util/symbol.h

@@ -6,6 +6,7 @@
 #include <linux/list.h>
 #include <linux/rbtree.h>
 #include "module.h"
+#include "event.h"
 
 struct symbol {
 	struct rb_node	rb_node;