r8169: preserve VLAN setting on RTL8125 in rtl_init_rxcfg

So far we set RX_VLAN_8125 unconditionally, even if
NETIF_F_HW_VLAN_CTAG_RX may not be set. Don't touch these bits,
and let only rtl8169_set_features() control them.

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