[][kernel][common][eth][Fix GMAC data corruption issue]

[Description]
Fix GMAC data corruption issue.

If without this patch, kernel might receive invalid packets that are corrupted by GMAC.

[Release-log]
N/A

Change-Id: I8a9f00402e4b8d9181a8c4c518665a16619cdc0a
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6398721
diff --git a/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 60939f2..54674ad 100755
--- a/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -581,7 +581,7 @@
 /* Mac control registers */
 #define MTK_MAC_MCR(x)		(0x10100 + (x * 0x100))
 #define MAC_MCR_MAX_RX_1536	BIT(24)
-#define MAC_MCR_IPG_CFG		(BIT(18) | BIT(16))
+#define MAC_MCR_IPG_CFG		(BIT(18) | BIT(16) | BIT(12))
 #define MAC_MCR_FORCE_MODE	BIT(15)
 #define MAC_MCR_TX_EN		BIT(14)
 #define MAC_MCR_RX_EN		BIT(13)