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 <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Link: https://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/include/linux/bitops.h

···
 #define _TOOLS_LINUX_BITOPS_H_
 
 #include <asm/types.h>
+#include <limits.h>
 #ifndef __WORDSIZE
 #define __WORDSIZE (__SIZEOF_LONG__ * 8)
 #endif