net: axi_emac: Use reg property for DMA registers

As per the xlnx,axi-ethernet-1.00.a DT documentation in linux, the AXI
DMA registers can be obtained via the reg property or via a separate
node for the axistream DMA controller. Currently only the latter is
supported, so add support to fetch the DMA controller registers from the
"reg" property.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20231116164024.139934-1-mchitale@ventanamicro.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/drivers/net/xilinx_axi_emac.c b/drivers/net/xilinx_axi_emac.c
index 54f2232..ef151ee 100644
--- a/drivers/net/xilinx_axi_emac.c
+++ b/drivers/net/xilinx_axi_emac.c
@@ -903,12 +903,11 @@
 
 	ret = dev_read_phandle_with_args(dev, "axistream-connected", NULL, 0, 0,
 					 &axistream_node);
-	if (ret) {
-		printf("%s: axistream is not found\n", __func__);
-		return -EINVAL;
-	}
+	if (!ret)
+		plat->dmatx = (struct axidma_reg *)ofnode_get_addr(axistream_node.node);
+	else
+		plat->dmatx = (struct axidma_reg *)dev_read_addr_index(dev, 1);
 
-	plat->dmatx = (struct axidma_reg *)ofnode_get_addr(axistream_node.node);
 	if (!plat->dmatx) {
 		printf("%s: axi_dma register space not found\n", __func__);
 		return -EINVAL;