kmod: append osversion to the portversion
The version is now
kmodpackagename-<kmodpackageversion>.<osversion>_<revision>,<epoch>
This is necessary to make sure that the same packages built on a newer
version of FreeBSD on a given branch is considered as an upgrade of the
default provided one.
In the current model of support, all packages are built on the lowest
supported version of a given branch, which means right now all packages
are built on 14.1, this results as since 14.2 has been released and up
to the time 14.1 is EOLed we do not provide working binary packages for
kernel modules and related for 14.2.
With this we will be able to provide a dedicated repo built against 14.2
that will be usable by users and pkg upgrade will simply update to the
right version.