atl1c: move tx napi into tpd_ring

To get more performance from using multiple tx queues one needs
a per tx queue napi.

Move tx napi from per adapter struct into per tx queue struct.
Patch that actually enables multiple tx queues will follow.

Signed-off-by: Gatis Peisenieks <gatis@mikrotik.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>