sfc: make TSO version a per-queue parameter

The Solarflare 8000 series NIC will use a new TSO scheme. The current
driver refuses to load if the current TSO scheme is not found. Remove
that check and instead make the TSO version a per-queue parameter.

Signed-off-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>