r8169: adjust the RxConfig settings.

Set the init value before reset in probe function. And then just
modify the relative bits and keep the init settings.

For 8110S, 8110SB, and 8110SC series, the initial value of RxConfig
needs to be set after the tx/rx is enabled.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>