net: dsa: mv88e6xxx: Fix SERDES support on 88E6141/6341

Version 1 of the patch adding SERDES support to the 88E6141/6341
correctly added the ops to the 88E6141/6341. However, by the time
version 3 was committed, the ops had moved to the 88E6085/6175. Put
them back where they belong.

Fixes: 5bafeb6e ("net: dsa: mv88e6xxx: 88E6141/6341 SERDES support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>