tools subcmd: Add missing NORETURN define for parse-options.h

parse-options.h uses the NORETURN macro without defining it. perf
doesn't see a build error because it defines the macro in util.h before
including parse-options.h. But any other tool including it will see an
error.

Define the macro in parse-options.h (if not already defined) so that
other tools can include it.

Signed-off-by: Josh Poimboeuf <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Bernd Petrovitsch <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Chris J Arges <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Michal Marek <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Pedro Alves <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/lib/subcmd/parse-options.h

···
 #include <stdbool.h>
 #include <stdint.h>
 
+#ifndef NORETURN
+#define NORETURN __attribute__((__noreturn__))
+#endif
+
 enum parse_opt_type {
 	/* special types */
 	OPTION_END,