mv643xx_eth: move a couple of init actions from ->open() to port probe

Move the netif_carrier_off() call in ->open() to port probe, so that
ethtool doesn't report the link as being up before we have up'd the
interface.

Move initialisation of the rx/tx coalescing timers from ->open() to
port probe, so that we don't reset the coalescing timers every time
the interface is up'd.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>