Stop using odp_time_to_u64() that is being removed from ODP.
Stop using odp_time_to_u64() that is being removed from ODP.

Use odp_time_to_ns() instead of odp_time_to_u64() that is not present
in ODP v1.15.0.0.

Signed-off-by: Janne Peltonen <184f24496cb678cb2ae7fb0b4232a4cbe2bea47a@nokia.com>
Reviewed-by: Brian Brooks <8e906ed46ccdc37d68771658f0f8f8740a374927@linaro.org>
Reviewed-by: Sorin Vultureanu <8013ba55f8675034bc2ab0d6c3a1c9650437ca36@enea.com>

TolikH/ofp,OpenFastPath/ofp,OpenFastPath/ofp,TolikH/ofp,TolikH/ofp,OpenFastPath/ofp,OpenFastPath/ofp