qed: Pass MAC hints to VFs

Some hypervisors can support MAC hints to their VFs.
Even though we don't have such a hypervisor API in linux, we add
sufficient logic for the VF to be able to receive such hints and
set the mac accordingly - as long as the VF has not been set with
a MAC already.

Signed-off-by: Yuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>