netdev: add qstat for csum complete

Recent commit 0cfe71f4

 ("netdev: add queue stats") added
a lot of useful stats, but only those immediately needed by virtio.
Presumably virtio does not support CHECKSUM_COMPLETE,
so statistic for that form of checksumming wasn't included.
Other drivers will definitely need it, in fact we expect it
to be needed in net-next soon (mlx5). So let's add the definition
of the counter for CHECKSUM_COMPLETE to uAPI in net already,
so that the counters are in a more natural order (all subsequent
counters have not been present in any released kernel, yet).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Fixes: 0cfe71f4 ("netdev: add queue stats")
Link: https://lore.kernel.org/r/20240529163547.3693194-1-kuba@kernel.org


Signed-off-by: Paolo Abeni <pabeni@redhat.com>