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/util.h

@@ -83,7 +83,6 @@
 #include <inttypes.h>
 #include "../../../include/linux/magic.h"
 
-#include "event.h"
 
 #ifndef NO_ICONV
 #include <iconv.h>