wifi: mt76: Add rx_queue_init callback

Introduce rx_queue_init DMA callback. This is a preliminary patch to
configure RRO RX queues and decouple RRO logic from WED support.

Co-developed-by: Rex Lu <rex.lu@mediatek.com>
Signed-off-by: Rex Lu <rex.lu@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250909-mt7996-rro-rework-v5-13-7d66f6eb7795@kernel.org


Signed-off-by: Felix Fietkau <nbd@nbd.name>