net: ti: icssg-prueth: Add phys_port_name support

Helps identifying the ports in udev rules e.g.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/895ae9c1-b6dd-4a97-be14-6f2b73c7b2b5@siemens.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>