bnx2x: Support PF <-> VF Bulletin Board

The PF <-> VF Bulletin Board is a simple interface between the
PF and the VF. The main reason for the Bulletin Board is to allow
the PF to be the initiator. The VF publishes at 'acquire' stage
the GPA of a Bulletin Board structure it has allocated. The PF notes
this GPA in the VF database. The VF samples the Bulletin Board
periodically for new messages. The latest version of the BB is always
used.

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>