net: bcmgenet: move DESC_INDEX flow to ring 0

[ Upstream commit 3b5d4f5 ]

The default transmit and receive packet handling is moved from
the DESC_INDEX (i.e. 16) descriptor rings to the Ring 0 queues.
This saves a fair amount of special case code by unifying the
handling.

A default dummy filter is enabled in the Hardware Filter Block
to route default receive packets to Ring 0.

Signed-off-by: Doug Berger <opendmb@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250306192643.2383632-7-opendmb@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 5393b2b ("net: bcmgenet: fix racing timeout handler")
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Doug Berger