8139cp: set ring address before enabling receiver

Currently, we enable the receiver before setting the ring address which could
lead the card DMA into unexpected areas. Solving this by set the ring address
before enabling the receiver.

btw. I find and test this in qemu as I didn't have a 8139cp card in hand. please
review it carefully.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>