r8169: restore mac addr in rtl8169_remove_one and rtl_shutdown

r8169: restore mac addr in rtl8169_remove_one and rtl_shutdown

The newer chipsets (all PCI-E) are known that they need full power cycle
(AC or battery removal) to reset MAC address to a  hardwired one. Previous
patch to address this problem loads the original MAC address from EEPROM.
But it brought other problem for which it is necessary to introduce a new
module parameter.
However, it might suffice to restore the initial MAC address before
shutdown/reboot/kexec and when removing the module.

Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>