net/parpd: Update to 1.2

While I'm here:

• Pacify portlint

Changelog:

• Extended to provide the needed IPv6 ND packets in addition to IPv4 ARP

PR: 235830
Submitted by: lutz@donnerhacke.de (maintainer)
Approved by: tcberner (mentor)
Differential Revision: https://reviews.freebsd.org/D19311