RDMA/mlx5: Enable decap and packet reformat on flow tables

If NIC RX flow tables support decap operation, enable it on creation,
This allows to perform decapsulation of tunnelled packets by steering
rules. If NIC TX flow tables support reformat operation, enable it on
creation.

We don't enable those capabilities on representors as the E-Switch should
handle packet modification (can be configured via TC) and as current
hardware can't handle both FDB and NIC flow tables with decap/packet
reformat support.

Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>