perf tools: Do not include stringify.h from the kernel sources

Use instead the copy just made to tools/include/linux/.

Cc: Adrian Hunter <adrian.hunter@intel.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-q736w12nwy98x5ox2hamp5ow@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/powerpc/util/header.c

@@ -3,9 +3,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-
-#include "../../util/header.h"
-#include "../../util/util.h"
+#include <linux/stringify.h>
 
 #define mfspr(rn)       ({unsigned long rval; \
 			 asm volatile("mfspr %0," __stringify(rn) \