bnx2x: VF fastpath

When VF driver is transmitting it must supply the correct mac
address in the parsing BD. This is used for firmware validation
and enforcement and also for tx-switching.
Refactor interrupt ack flow to allow for different BAR addresses of
the hardware in the PF BAR vs the VF BAR.

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>