net/mlx5e: Move to use common phys port names for vport representors

With VF LAG commit 491c37e4 "net/mlx5e: In case of LAG, one switch
parent id is used for all representors", both uplinks and all the VFs
(on both of them) get the same switchdev id.

This cause the provisioning system method to identify the rep of a given
VF from the parent PF PCI device using switchev id and physical port
name to break, since VFm of PF0 will have the (id, name) as VFm of PF1.

To fix that, we align to use the framework agreed upstream and set by
nfp commit 168c478e "nfp: wire get_phys_port_name on representors":

$ cat /sys/class/net/eth4_*/phys_port_name
p0
pf0vf0
pf0vf1

Now, the names will be different, e.g. pf0vf0 vs. pf1vf0.

Fixes: 491c37e4 ("net/mlx5e: In case of LAG, one switch parent id is used for all representors")
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reported-by: Waleed Musa <waleedm@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>