The dual-port Ether configurations always have a shared TSU to e.g. pass
the packets between those  ports.  With the  TSU init. code gathered under
the single *if*, we now can only get the port # from 'platform_device::id'
only when we actually  need it  (and not recalculate it each time)...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>