bnx2x: Prepare device and initialize VF database

At nic load of the PF, if VFs may be present, prepare the device
for the VFs. Initialize the VF database in preparation of VF arrival.

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>