net: ethernet: mediatek: Use NET_IP_ALIGN to judge if HW RX_2BYTE_OFFSET is enabled

Should only enable HW RX_2BYTE_OFFSET function in the case NET_IP_ALIGN
equals to 2.
Signed-off-by: Mark Lee <mark-mc.lee@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mediatek/mtk_eth_soc.c

@@ -1778,6 +1778,7 @@ static void mtk_poll_controller(struct net_device *dev)
 
 static int mtk_start_dma(struct mtk_eth *eth)
 {
+	u32 rx_2b_offset = (NET_IP_ALIGN == 2) ? MTK_RX_2B_OFFSET : 0;
 	int err;
 
 	err = mtk_dma_init(eth);
@@ -1794,7 +1795,7 @@ static int mtk_start_dma(struct mtk_eth *eth)
 		MTK_QDMA_GLO_CFG);
 
 	mtk_w32(eth,
-		MTK_RX_DMA_EN | MTK_RX_2B_OFFSET |
+		MTK_RX_DMA_EN | rx_2b_offset |
 		MTK_RX_BT_32DWORDS | MTK_MULTI_EN,
 		MTK_PDMA_GLO_CFG);