tools headers: Add limits.h to access __WORDSIZE

We need to make sure limits.h is included before checking if we can use
__WORDSIZE, do it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-5yfoed4rnsck2n3cwhm9mvth@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/include/linux/bitops.h

@@ -3,6 +3,7 @@
 #define _TOOLS_LINUX_BITOPS_H_
 
 #include <asm/types.h>
+#include <limits.h>
 #ifndef __WORDSIZE
 #define __WORDSIZE (__SIZEOF_LONG__ * 8)
 #endif