arm64: dts: mediatek: mt7986: add support for RX Wireless Ethernet Dispatch

Similar to TX Wireless Ethernet Dispatch, introduce RX Wireless Ethernet
Dispatch to offload traffic received by the wlan interface to lan/wan
one.

Co-developed-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>