MINOR: tinfo/clock: turn sched_call_date to 64-bits

MINOR: tinfo/clock: turn sched_call_date to 64-bits

We used to store it in 32-bits since we'd only use it for latency and CPU
usage calculation but usages will evolve so let's not truncate the value
anymore. Now we store the full 64 bits. Note that this doesn't even
increase the storage size due to alignment. The 3 usage places were
verified to still be valid (most were already cast to 32 bits anyway).