net: atlantic: A2 hw_ops skeleton

This patch adds basic hw_ops layout for A2.

Actual implementation will be added in the follow-up patches.

Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>