bnx2x: (NPAR mode) Fix FW initialization

Fix FW initialization according to max BW stored in percents
 for NPAR mode. Protect HW from being configured to speed 0.

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>