bnx2x: VF can report link speed

Until now VFs were oblvious to the actual configured link parameters.
This patch does 2 things:

  1. It enables a PF to inform its VF using the bulletin board of the link
     configured, and allows the VF to present that information.

  2. It adds support of `ndo_set_vf_link_state', allowing the hypervisor
     to set the VF link state.

Signed-off-by: Dmitry Kravkov <Dmitry.Kravkov@qlogic.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>