r8169: reset chip synchronously in __rtl8169_resume

Triggering an asynchronous reset is problematic for the following
reasons, therefore reset the chip synchronously.

- The reset routine resets registers and parameters behind our back
  what may collide with code executed after triggering the reset.

- __rtl8169_resume() is called as part of pm_runtime_get_sync() and
  callers expect that the chip is fully resumed afterwards.

In context of this driver triggering an asynchonous reset should be
considered an emergency procedure.

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