bnx2x: handle iSCSI SD mode

bnx2x: handle iSCSI SD mode

in iSCSI SD mode to bnx2x device assigned single mac address
which is supposted to be iscsi mac. If this mode is recognized
bnx2x will disable LRO, decrease number of queues to 1 and rx ring
size to the minumum allowed by FW, this in order minimize memory use.
It will tranfer mac for iscsi usage and zero primary mac of the netdev.

(cherry picked from commit 614c76df1d1224dc2eee8678fab6e0b95b49b7da)
Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Joe Jin <joe.jin@oracle.com>