net/mlx5: fix flow engine type in function name

net/mlx5: fix flow engine type in function name

The concrete function names have a prefix for flow_dv.
This emphasizes the flow engine is Direct Verbs.

The function flow_get_aged_flows doesn’t have this prefix.
It creates an inconsistency with the other functions.

Update the function name to include dv.

Fixes: fa2d01c87d2 ("net/mlx5: support flow aging")
Cc: stable@dpdk.org
Signed-off-by: Asaf Penso <asafp@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>