net: pcs: xpcs: delete shim definition for mdio_xpcs_get_ops()

CONFIG_STMMAC_ETH selects CONFIG_PCS_XPCS, so there should be no
situation where the shim should be needed.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/pcs/pcs-xpcs.h

@@ -36,13 +36,6 @@ struct mdio_xpcs_ops {
 			  int enable);
 };
 
-#if IS_ENABLED(CONFIG_PCS_XPCS)
 struct mdio_xpcs_ops *mdio_xpcs_get_ops(void);
-#else
-static inline struct mdio_xpcs_ops *mdio_xpcs_get_ops(void)
-{
-	return NULL;
-}
-#endif
 
 #endif /* __LINUX_PCS_XPCS_H */