net: pcs: lynx: use mdiodev accessors

Use the recently introduced mdiodev accessors for the lynx PCS.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/E1o3Zd8-002yHI-G2@rmk-PC.armlinux.org.uk


Signed-off-by: Jakub Kicinski <kuba@kernel.org>