s390/qeth: Detect PNSO OC3 capability

This patch detects whether device-to-bridge-notification, provided
by the Perform Network Subchannel Operation (PNSO) operation code
ADDR_INFO (OC3), is supported by this card. A following patch will
map this to the learning_sync bridgeport flag, so we store it in
priv->brport_hw_features in bridgeport flag format.

Only IQD cards provide PNSO.
There is a feature bit to indicate whether the machine provides OC3,
unfortunately it is not set on old machines.
So PNSO is called to find out. As this will disable notification
and is exclusive with bridgeport_notification, this must be done
during card initialisation before previous settings are restored.

PNSO functionality requires some configuration values that are added to
the qeth_card.info structure. Some helper functions are defined to fill
them out when the card is brought online and some other places are
adapted, that can also benefit from these fields.

Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>