Currently PF and VF representors are exposed as virtual device.
They are not linked to its parent PCI device like how uplink
representor is linked.
Due to this, PF and VF representors cannot benefit of the
systemd defined naming scheme. This requires special handling
by the users.

Hence, link the PF and VF representors to their parent PCI device
similar to existing uplink representor netdevice.

Example:
udevadm output before linking to PCI device:
$ udevadm test-builtin net_id  /sys/class/net/eth6
Load module index
Network interface NamePolicy= disabled on kernel command line, ignoring.
Parsed configuration file /usr/lib/systemd/network/99-default.link
Created link configuration context.
Using default interface naming scheme 'v243'.
ID_NET_NAMING_SCHEME=v243
Unload module index
Unloaded link configuration context.

udevadm output after linking to PCI device:
$ udevadm test-builtin net_id /sys/class/net/eth6
Load module index
Network interface NamePolicy= disabled on kernel command line, ignoring.
Parsed configuration file /usr/lib/systemd/network/99-default.link
Created link configuration context.
Using default interface naming scheme 'v243'.
ID_NET_NAMING_SCHEME=v243
ID_NET_NAME_PATH=enp0s8f0npf0vf0
Unload module index
Unloaded link configuration context.

In past there was little concern over seeing 10,000 lines output
showing up at thread [1] is not applicable as ndo ops for VF
handling is not exposed for all the 100 repesentors for mlx5 devices.

Additionally alternative device naming [2] to overcome shorter device
naming is also part of the latest systemd release v245.

[1] https://marc.info/?l=linux-netdev&m=152657949117904&w=2
[2] https://lwn.net/Articles/814068/Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>