serial: bfin-uart: Add tty ASYNC_CTS_FLOW flag to do CTS flow control.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/bfin_uart.c

@@ -1377,8 +1377,10 @@ static int bfin_serial_probe(struct platform_device *pdev)
 		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 		if (res == NULL)
 			uart->cts_pin = -1;
-		else
+		else {
 			uart->cts_pin = res->start;
+			uart->port.flags |= ASYNC_CTS_FLOW;
+		}
 
 		res = platform_get_resource(pdev, IORESOURCE_IO, 1);
 		if (res == NULL)