Merge linuxptp from Debian Unstable for resolute

[Lukas Märdian]

As per SD-2569 we want to have linuxptp >= 4.4. for 26.04 LTS.

To be merged from Debian or upstream.

Important note from Salsa (https://salsa.debian.org/multimedia-team/linuxptp/-/merge_requests/4):

"""
Upstream supports 4 different cryptographic libraries to enable this features:

- GnuPG
- GnuTLS
- Nettle
- OpenSSL

I decided to go with Nettle because it was the least burdensome choice. OpenSSL enforces a license change to GPLv3 on LinuxPTP, GnuTLS depends on nettle-dev so we end up with both the Nettle and GnuTLS backends enabled if we don’t patch the upstream source and I did not considerate GnuPG.
"""

=> going with Nettle should be fine as long as the package stays in universe.

[Lukas Märdian (slyon)]

See https://salsa.debian.org/multimedia-team/linuxptp/-/merge_requests/4 and upstream (watch file) changes

https://downloads.nwtime.org/linuxptp/
https://github.com/nwtime/linuxptp
upstream moved: https://bugs.launchpad.net/ubuntu/+source/linuxptp/+bug/2115203

[Lukas Märdian (slyon)]

PPA: https://launchpad.net/~slyon/+archive/ubuntu/merge-lp2130003-resolute
MP: https://code.launchpad.net/~slyon/ubuntu/+source/linuxptp/+git/linuxptp/+merge/497354