net: mediatek: fix usability with wget command

The wget command currently cannot work correctly with mtk_eth driver.
This patch fixed this by increase DMA ring size and invalidate ring data
after use.

diff --git a/drivers/net/mtk_eth.c b/drivers/net/mtk_eth.c
index 888e8c1..454caa3 100644
--- a/drivers/net/mtk_eth.c
+++ b/drivers/net/mtk_eth.c
@@ -29,8 +29,8 @@
 
 #include "mtk_eth.h"
 
-#define NUM_TX_DESC		24
-#define NUM_RX_DESC		24
+#define NUM_TX_DESC		32
+#define NUM_RX_DESC		32
 #define TX_TOTAL_BUF_SIZE	(NUM_TX_DESC * PKTSIZE_ALIGN)
 #define RX_TOTAL_BUF_SIZE	(NUM_RX_DESC * PKTSIZE_ALIGN)
 #define TOTAL_PKT_BUF_SIZE	(TX_TOTAL_BUF_SIZE + RX_TOTAL_BUF_SIZE)
@@ -1897,6 +1897,9 @@
 
 	rxd = priv->rx_ring_noc + idx * priv->soc->rxd_size;
 
+	invalidate_dcache_range((ulong)rxd->rxd1,
+				(ulong)rxd->rxd1 + PKTSIZE_ALIGN);
+
 	if (MTK_HAS_CAPS(priv->soc->caps, MTK_NETSYS_V2) ||
 	    MTK_HAS_CAPS(priv->soc->caps, MTK_NETSYS_V3))
 		rxd->rxd2 = PDMA_V2_RXD2_PLEN0_SET(PKTSIZE_ALIGN);