selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"

Trivial fix to spelling mistake

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Link: http://lkml.kernel.org/r/1480372524-15181-2-git-send-email-john.stultz@linaro.org


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>