Simplify tests on configuration ranges.

This patch simplifies some expressions which validate that configuration
variables are within the allowed ranges.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
phc2sys: enable PPS output from PHC

PPS output from a PHC has to be enabled by PTP_ENABLE_PPS ioctl. Call
the ioctl when both PHC device and PPS device are specified and PPS is
supported by the PHC.

Signed-off-by: Jiri Benc <jbenc@redhat.com>