amd-xgbe: Set DMA mask based on hardware register value

The hardware supplies a value that indicates the DMA range that it
is capable of using. Use this value rather than hard-coding it in
the driver.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe.h b/drivers/net/ethernet/amd/xgbe/xgbe.h
index 1eea3e5..bfe11fb 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe.h
+++ b/drivers/net/ethernet/amd/xgbe/xgbe.h
@@ -632,6 +632,7 @@
 	unsigned int rx_fifo_size;	/* MTL Receive FIFO Size */
 	unsigned int tx_fifo_size;	/* MTL Transmit FIFO Size */
 	unsigned int adv_ts_hi;		/* Advance Timestamping High Word */
+	unsigned int dma_width;		/* DMA width */
 	unsigned int dcb;		/* DCB Feature */
 	unsigned int sph;		/* Split Header Feature */
 	unsigned int tso;		/* TCP Segmentation Offload */