r8169: improve configuring RxConfig register

r8169: improve configuring RxConfig register

Two bits in RxConfig are controlled by the following dev->feature's:
- NETIF_F_RXALL
- NETIF_F_HW_VLAN_CTAG_RX (since RTL8125)

We have to take care that RxConfig gets fully configured in
rtl_hw_start() after e.g. resume from hibernation. Therefore:

- Factor out setting the feature-controlled RxConfig bits to a new
  function rtl_set_rx_config_features() that is called from
  rtl8169_set_features() and rtl_hw_start().
- Don't deal with RX_VLAN_8125 in rtl_init_rxcfg(), it will be set
  by rtl_set_rx_config_features().
- Don't handle NETIF_F_RXALL in rtl_set_rx_mode().

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