ptp4l: Allow P, I constants over 1.0.

With sub-second sync intervals, it may be useful to set P and I to
values over 1.0.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
phc2sys: Use currentUtcOffset only with PTP timescale.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>