net/mlx5: fix default minimal data inline

net/mlx5: fix default minimal data inline

The patch [Fixes] sets the default value of required minimal
inline data to 0 bytes. On some configurations (depends
on switchdev/legacy settings and FW version/settings)
the ConnectX-4LX NIC requires minimal 18 bytes of
Tx descriptor inline data to operate correctly.

Wrongly set to 0 default value may prevent NIC from operating
with out-of-the-box settings, this patch reverts default
value for ConnectX-4LX back to 18 bytes (inline L2).

Fixes: 9f350504bb32 ("net/mlx5: fix ConnectX-4LX minimal inline data limit")
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>