PM: fix clock_gettime() nanosecond overflow
PM: fix clock_gettime() nanosecond overflow

Change-Id: I969b30862cb671200a26b55afe3d523b6cfd2a7c

veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi