This patch sets the automatic speed and duplex detection bits
in MAC_CR to enable the mac to determine its speed automatically
from the phy.

Note this must be done BEFORE the receiver or transmitter is
enabled.
Signed-off-by: NStephane Fillod <fillods@users.sf.net>
Signed-off-by: NSteve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>