Log Message:
This adds rc.d scripts. The ntp.conf is example from official NetBSD.
The rc.d scripts are based on official NetBSD scripts.

This also adds:
CONFIGURE_ARGS+=--sysconfdir=${PKG_SYSCONFDIR}

This was discussed and okayed with maintainer, fredb, in February,

Currently, the ntpd.sh rc.d script has a note about the
ntpd_chrootdir is only for NetBSD at this time. (Because I haven't
tested under other operating systems.)