r8169: load Realtek PHY driver module before r8169

This soft dependency works around an issue where sometimes the genphy
driver is used instead of the dedicated PHY driver. The root cause of
the issue isn't clear yet. People reported the unloading/re-loading
module r8169 helps, and also configuring this soft dependency in
the modprobe config files. Important just seems to be that the
realtek module is loaded before r8169.

Once this has been applied preliminary fix 38af4b903210 ("net: phy:
add workaround for issue where PHY driver doesn't bind to the device")
will be removed.

Fixes: f1e911d5

 ("r8169: add basic phylib support")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>