Set RX scatter gather number to 4 in order to extend the maximum AMSDU
size to 11,454.
Signed-off-by: Sean Wang <sean.wang@mediatek.com> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Felix Fietkau <nbd@nbd.name>