net/mlx5: fix GENEVE tunnel flow validation

net/mlx5: fix GENEVE tunnel flow validation

The new Mellanox devices support GENEVE tunnel stateless offloads by
native HW parsers, FW doesn't need to configure flex parser to support
it.

The FW capability for GENEVE flex parser is not set for the above
devices, hence the GENEVE flow validation failed for them.

Remove the flex parser validation for GENEVE, stay only with the direct
FW capability for GENEVE support.

Fixes: e59a5dbcfd07 ("net/mlx5: add flow match on GENEVE item")
Cc: stable@dpdk.org
Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>