tty: serial: uartlite: use clk_disable_unprepare to match clk_prepare_enable

The driver uses clk_prepare_enable in ulite_probe but uses clk_unprepare
in ulite_remove, which does not match.
Replace clk_unprepare with clk_disable_unprepare to fix it.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20191101085433.10399-1-hslester96@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/uartlite.c

@@ -862,7 +862,7 @@ static int ulite_remove(struct platform_device *pdev)
 	struct uartlite_data *pdata = port->private_data;
 	int rc;
 
-	clk_unprepare(pdata->clk);
+	clk_disable_unprepare(pdata->clk);
 	rc = ulite_release(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);