selftests/timers: Add nsleep-lat test from timetest suite
Adds my nanosleep latency test from the timetest suite.
This checks to make sure we don't see "unreasonable"
latencies (> 40ms) when calling nanosleep.
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: John Stultz <john.stultz@linaro.org> Tested-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>