r8169: simplify rtl_hw_start_8169

Currently done:
- if mac_version in (01, 02, 03, 04)
	RTL_W8(tp, ChipCmd, CmdTxEnb | CmdRxEnb);
- if mac_version in (01, 02, 03, 04)
	rtl_set_rx_tx_config_registers(tp);
- if mac_version not in (01, 02, 03, 04)
	RTL_W8(tp, ChipCmd, CmdTxEnb | CmdRxEnb);
	rtl_set_rx_tx_config_registers(tp);

So we do exactly the same independent of chip version and can simplify
the code.

In addition remove the call to rtl_init_rxcfg(), it's called in
rtl_init_one() already and the set bits are never touched later.
rtl_init_8168/8101 don't include this call either.

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