IB: Let ib_core resolve destination mac address

Since IB/core resolves the destination mac address for user and kernel
consumers, avoid resolving in multiple provider drivers.

Only ib_core resolves DMAC now, therefore resolve_eth_dmac is removed as
exported symbol.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/ah.c

@@ -89,10 +89,6 @@ struct ib_ah *mlx5_ib_create_ah(struct ib_pd *pd, struct rdma_ah_attr *ah_attr,
 
 		resp.response_length = min_resp_len;
 
-		err = ib_resolve_eth_dmac(pd->device, ah_attr);
-		if (err)
-			return ERR_PTR(err);
-
 		memcpy(resp.dmac, ah_attr->roce.dmac, ETH_ALEN);
 		err = ib_copy_to_udata(udata, &resp, resp.response_length);
 		if (err)