Integrate meta-guf-distro/hardknott-dhcpcd-enable-hostname-propagation

Commit: https://gitlab.com/garz-fricke/yocto/layers/meta-guf-distro/-/commit/d8492cf72e5833b8f3976275e2fac3cd8f7476ea

dhcpcd: Enable hostname propagation

Removed the config and append file for dhclient.conf as it does not
exist any more.
Enabled hostname propagation as (hopefully) was done for dhclient before
for dhcpcd which replaced dhclient.

BCS 746-000339