drivers/net: enic: Adding support for Cisco Low Latency NIC

This patch,
    - Adds new firmware commands for the new Cisco Low Latency NIC
      (aka. USNIC).

Signed-off-by: Neel Patel <neepatel@cisco.com>
Signed-off-by: Nishank Trivedi <nistrive@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>