net/mlx5: mlx5e_hv_vhca_stats_create return type to void

Callers of this functions ignore its return value, as reported by
Wang Qing, in one of the return paths, it returns positive values.

Since return value is ignored anyways, void out the return type of the
function.

Reported-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

net/mlx5e: Add mlx5e HV VHCA stats agent

HV VHCA stats agent is responsible on running a preiodic rx/tx
packets/bytes stats update. Currently the supported format is version
MLX5_HV_VHCA_STATS_VERSION. Block ID 1 is dedicated for statistics data
transfer from the VF to the PF.

The reporter fetch the statistics data from all opened channels, fill it
in a buffer and send it to mlx5_hv_vhca_write_agent.

As the stats layer should include some metadata per block (sequence and
offset), the HV VHCA layer shall modify the buffer before actually send it
over block 1.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>