bnx2x: Allow management traffic after boot from SAN

As part of the previous driver unload flow, whenever bnx2x is
loaded after the UNDI driver it closes all Rx traffic.
However, this leads to management traffic also being stopped until
the network interface associated with one of its functions gets loaded.

To remedy this, management traffic is re-opened once the 'cleaning'
after the previous driver ends.

Signed-off-by: Barak Witkowski <barak@broadcom.com>
Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>