net: phy: smsc: force all capable mode if the phy is started in powerdown mode

A SMSC PHY in power down mode can't be used.
If a SMSC PHY is in this mode in the config_init
stage, the mode "all capable" is set. So the PHY
could then be used.

Signed-off-by: Philippe Reynes <tremyfr@yahoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>