[PATCH] doc: announce removal of flow director

[Thomas Monjalon]

28/05/2026 19:00, Stephen Hemminger:
> There are still leftover bits in ethdev related to flow director (fdir).
> Will be removing these in 26.11 so give final notice.
> 
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
> +* ethdev: The legacy filtering data structures in ``rte_eth_ctrl.h``,
> +  including the flow director (FDIR) types (``rte_eth_fdir_*``, ``rte_fdir_*``)
> +  and the ntuple/ethertype/SYN/tunnel/input-set filter types, are superseded
> +  by the ``rte_flow`` API and will be removed in DPDK 26.11. The associated
> +  driver-facing definitions in ``ethdev_driver.h`` (``RTE_ETH_FILTER_FDIR``,
> +  ``struct rte_eth_fdir_conf``, ``enum rte_eth_fdir_pballoc_type``,
> +  ``enum rte_fdir_status_mode``) will be removed at the same time.

The problem is that some drivers rely on these structures for rte_flow.

Note: this file is big, please keep it sorted by moving this
close to other ethdev and flow deprecations.