Documentation/timers/hpet_example.c: add supporting info for hpet_example

$./hpet_example info /dev/hpet
-hpet: executing info
hpet_info: hi_irqfreq 0x0 hi_flags 0x0 hi_hpet 0 hi_timer 2

Signed-off-by: Jaswinder Singh Rajput <[e-mail]>
Cc: Clemens Ladisch <[e-mail]>
Cc: "Venkatesh Pallipadi (Venki)" <[e-mail]>
Cc: john stultz <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/timers/hpet_example.c

···
 void
 hpet_info(int argc, const char **argv)
 {
+	struct hpet_info	info;
+	int			fd;
+
+	if (argc != 1) {
+		fprintf(stderr, "hpet_info: device-name\n");
+		return;
+	}
+
+	fd = open(argv[0], O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "hpet_info: open of %s failed\n", argv[0]);
+		return;
+	}
+
+	if (ioctl(fd, HPET_INFO, &info) < 0) {
+		fprintf(stderr, "hpet_info: failed to get info\n");
+		goto out;
+	}
+
+	fprintf(stderr, "hpet_info: hi_irqfreq 0x%lx hi_flags 0x%lx ",
+		info.hi_ireqfreq, info.hi_flags);
+	fprintf(stderr, "hi_hpet %d hi_timer %d\n",
+		info.hi_hpet, info.hi_timer);
+
+out:
+	close(fd);
+	return;
 }
 
 void