net/sfc: do not push fast free offload to default TxQ config

net/sfc: do not push fast free offload to default TxQ config

Doing so is wrong since fast free is an adapter-wide offload.

Technically, the offending commit (see "Fixes" tag) does not
induce failures, however, such started to occur after commit
a4996bd89c42 ("ethdev: new Rx/Tx offloads API") had shown up,
because of the strict offload validation in the generic code.

Fixes: c78d280e88ef ("net/sfc: convert to new Tx offload API")
Cc: stable@dpdk.org
Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>