ptp: idt82p33: optimize _idt82p33_adjfine

Use div_s64 so that the neg_adj is not needed.

Signed-off-by: Min Li <min.li.xe@renesas.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/1604634729-24960-3-git-send-email-min.li.xe@renesas.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>