serial: ifx6x60: add missed pm_runtime_disable

The driver forgets to call pm_runtime_disable in remove.
Add the missed calls to fix it.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191118024833.21587-1-hslester96@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/ifx6x60.c

@@ -1230,6 +1230,9 @@ static int ifx_spi_spi_remove(struct spi_device *spi)
 	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
 	/* stop activity */
 	tasklet_kill(&ifx_dev->io_work_tasklet);
+
+	pm_runtime_disable(&spi->dev);
+
 	/* free irq */
 	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
 	free_irq(gpio_to_irq(ifx_dev->gpio.srdy), ifx_dev);