r8169: fix RTL8168f/RTL8411 EPHY config

Mistakenly bit 2 was set instead of bit 3 as in the vendor driver.

Fixes: a7a92cf8 ("r8169: sync PCIe PHY init with vendor driver 8.047.01")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>