Looks like a bug on FSP 5.1.0 when using non listed PHY device

The default code generated in r_ether_phy.c doesn't pass compilation when you select your own phy (none of the listed ones).

The correct sentence should be  p_callback->p_target_init(p_instance_ctrl);  in ether_phy_targets_initialize at line 1032 (and 1030), same applies for 

  result = p_callback->p_target_link_partner_ability_get(p_instance_ctrl, line_speed_duplex); at line 1109 (and 1107) in function ether_phy_targets_is_support_link_partner_ability