bnx2x: changed initial dcb configuration

The changes were mostly made to enable back-to-back data flow with dcb.
Other changes were simply deemed as a better 'clean' initial configuration.

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>