nds32: ftmac100: support cache enable.

Add cache inval and flush when rx and tx.

Signed-off-by: rick <rick@andestech.com>
diff --git a/drivers/net/ftmac100.c b/drivers/net/ftmac100.c
index f231e6b..4e45f00 100644
--- a/drivers/net/ftmac100.c
+++ b/drivers/net/ftmac100.c
@@ -79,7 +79,6 @@
 	struct ftmac100_rxdes *rxdes = priv->rxdes;
 	unsigned int maccr;
 	int i;
-
 	debug ("%s()\n", __func__);
 
 	ftmac100_reset(priv);
@@ -156,7 +155,6 @@
 	unsigned short rxlen;
 
 	curr_des = &priv->rxdes[priv->rx_index];
-
 	if (curr_des->rxdes0 & FTMAC100_RXDES0_RXDMA_OWN)
 		return 0;
 
@@ -169,7 +167,7 @@
 	}
 
 	rxlen = FTMAC100_RXDES0_RFL (curr_des->rxdes0);
-
+	invalidate_dcache_range(curr_des->rxdes2,curr_des->rxdes2+rxlen);
 	debug ("%s(): RX buffer %d, %x received\n",
 	       __func__, priv->rx_index, rxlen);
 
@@ -196,6 +194,7 @@
 
 	/* initiate a transmit sequence */
 
+	flush_dcache_range((u32)packet,(u32)packet+length);
 	curr_des->txdes2 = (unsigned int)packet;	/* TXBUF_BADR */
 
 	curr_des->txdes1 &= FTMAC100_TXDES1_EDOTR;