linux(4): Implement semtimedop syscalls.

On i386 are two semtimedop. The old one is called via multiplexor and
uses 32-bit timespec, and new semtimedop_tim64, which is uses 64-bit
timespec.

MFC after: 2 weeks

(cherry picked from commit 3245a2ecea21ace3d97cec1266fbe29c88ba1a59)