kselftests: timers: Increase delay between suspends in alarmtimer-suspend

When testing on some hardware, waiting only a second before
re-triggering suspend can keep TCP connections from re-establishing
which after a number of cycles can cause TCP connections to close
while the test is running.

So extend the delay between suspend calls to 3 seconds to let
the connections stay alive.

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/timers/alarmtimer-suspend.c

@@ -172,7 +172,7 @@ int main(void)
 		while (alarmcount < 10) {
 			int ret;
 
-			sleep(1);
+			sleep(3);
 			ret = system("echo mem > /sys/power/state");
 			if (ret)
 				break;