Merge branch 'ptp-ns_to_timespec64'

Richard Cochran says:

====================
ptp: remove open coded ns_to_timespec64 and reverse

This patch series is a follow up to the recent timespec64 work for the
PTP Hardware Clock drivers.  Arnd noticed that drivers are using open
coded implementations of ns_to_timespec64 and timespec64_to_ns.  This
series replaces the open coded logic with the helper functions.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>