enic: Add ndo_set_vf_mac support for enic dynamic devices

This patch implements the ndo_set_vf_mac netdev operation for enic
dynamic devices. It treats the mac address set by IFLA_VF_MAC as a
special case to use it in the port profile provisioning data.

Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: David Wang <dwang2@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>