bnx2x: Enhance MAC configuration for VFs

Improved support for adding/removing vf mac addresses.

This includes the case where HyperVisor forced the address (sampled from
bulletin board), and the case where it did not in which the VF can
configure its own mac address.

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