net/mlx5: fix raw encap/decap limit

net/mlx5: fix raw encap/decap limit

The MLX5_ENCAPSULATION_DECISION_SIZE constant is used
to check the raw encap/decap actions for the raw header
size. The header is constructed of the rte_xxx_hdr
structures instead of rte items. Hence, constant
must be defined with rte_xxx_hdr structure sizes.

Fixes: 50f576d657d7 ("net/mlx5: fix VLAN actions in meter")
Cc: stable@dpdk.org
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
Acked-by: Ori Kam <orika@nvidia.com>
Acked-by: Suanming Mou <suanmingm@nvidia.com>