net: fec: remove workaround to restart phylib state machine on MDIO timeout

There's a workaround to restart the phylib state machine in case of a
MDIO access timeout. Seems it was introduced to deal with the
consequences of a too small MDIO timeout. See also commit message of
c3b084c2

 ("net: fec: Adjust ENET MDIO timeouts") which increased
the timeout value later. Due to the later timeout value fix it seems
to be safe to remove the workaround.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>