clock_settime/clock_settime_8-1: hardly ever passes

This test hardly ever passes with recent kernels. I have made different tests in different architectures:

https://bugs.linaro.org/show_bug.cgi?id=3965#c13
https://bugs.linaro.org/show_bug.cgi?id=3965#c14
https://bugs.linaro.org/show_bug.cgi?id=3965#c15

and I would say 95% of the times this test fails with a DELTA time of 2 seconds, when the acceptable DELTA would be just 1 second. 