net: stmmac: use readl_poll_timeout() function in dwmac4_dma_reset()

The dwmac4_dma_reset() function use an open coded of readl_poll_timeout().
Replace the open coded handling with the proper function.
Signed-off-by: NDejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c

@@ -6,6 +6,7 @@
  */
 
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/delay.h>
 #include "common.h"
 #include "dwmac4_dma.h"
@@ -14,22 +15,14 @@
 int dwmac4_dma_reset(void __iomem *ioaddr)
 {
 	u32 value = readl(ioaddr + DMA_BUS_MODE);
-	int limit;
 
 	/* DMA SW reset */
 	value |= DMA_BUS_MODE_SFT_RESET;
 	writel(value, ioaddr + DMA_BUS_MODE);
-	limit = 10;
-	while (limit--) {
-		if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET))
-			break;
-		mdelay(10);
-	}
-
-	if (limit < 0)
-		return -EBUSY;
 
-	return 0;
+	return readl_poll_timeout(ioaddr + DMA_BUS_MODE, value,
+				 !(value & DMA_BUS_MODE_SFT_RESET),
+				 10000, 100000);
 }
 
 void dwmac4_set_rx_tail_ptr(void __iomem *ioaddr, u32 tail_ptr, u32 chan)