net: airoha: configure QoS channel for HW accelerated flowtable traffic

net: airoha: configure QoS channel for HW accelerated flowtable traffic

As done for the SW path, configure the QoS channel for HW accelerated
traffic according to the user port index when forwarding to a DSA port,
or rely on the GDM port identifier otherwise. This allows HTB shaping
to be applied to HW accelerated traffic.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260430-airoha-ppe-qos-channel-v1-1-5ef9221e85c1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>