realtek: rtl839x: support rtl8214fc on rtl8393

realtek: rtl839x: support rtl8214fc on rtl8393

Returning ENODEV in rtl8214fc_phy_probe when an RTL8393 SoC is detected
makes it impossible to use an external RTL8214FC PHY on the SoC.
Instead, just skip rtl8380_configure_rtl8214fc on RTL8393. This seems to
make both combo and SFP-only ports on the Edgecore ECS4100-12PH work
properly.

However, this will probably break ports connected to RTL8218B PHYs at
addresses 24 or higher, as both RTL8214FC and RTL8218B have the same PHY
id, and rtl8214fc_match_phy_device matches devices with that ID and PHY
addr above 24 (e.g D-Link DGS-1210-52).