net/mlx5e: Change skb fifo push/pop API to be used without SQ

The skb fifo push/pop API used pre-defined attributes within the
mlx5e_txqsq.
In order to share the skb fifo API with other non-SQ use cases,
change the API input to get newly defined mlx5e_skb_fifo struct.

Signed-off-by: Eran Ben Elisha <eranbe@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>