ar933x: serial: Remove the explicit pinctrl setting

The correct pinctrl is handled automatically so we don't need to do it in
the driver.

Signed-off-by: Wills Wang <wills.wang@live.com>
diff --git a/drivers/serial/serial_ar933x.c b/drivers/serial/serial_ar933x.c
index d43f9c9..aae66dc 100644
--- a/drivers/serial/serial_ar933x.c
+++ b/drivers/serial/serial_ar933x.c
@@ -38,6 +38,7 @@
 };
 
 /*
+ * Baudrate algorithm come from Linux/drivers/tty/serial/ar933x_uart.c
  * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
  */
 static u32 ar933x_serial_get_baud(u32 clk, u32 scale, u32 step)
@@ -145,27 +146,14 @@
 static int ar933x_serial_probe(struct udevice *dev)
 {
 	struct ar933x_serial_priv *priv = dev_get_priv(dev);
-	struct udevice *pinctrl;
 	fdt_addr_t addr;
 	u32 val;
-	int ret;
-
-	ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
-	if (ret)
-		return ret;
-	ret = pinctrl_get_periph_id(pinctrl, dev);
-	if (ret < 0)
-		return ret;
-	ret = pinctrl_request(pinctrl, ret, 0);
-	if (ret < 0)
-		return ret;
 
 	addr = dev_get_addr(dev);
 	if (addr == FDT_ADDR_T_NONE)
 		return -EINVAL;
 
-	priv->regs = map_physmem(addr,
-				 AR933X_UART_SIZE,
+	priv->regs = map_physmem(addr, AR933X_UART_SIZE,
 				 MAP_NOCACHE);
 
 	/*