serial: stm32: select pinctrl state in each suspend/resume function

Select either pinctrl sleep state in suspend function or default state in
resume function.

Signed-off-by: Bich Hemon <[e-mail]>
Signed-off-by: Erwan Le Ray <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/stm32-usart.c

···
 	else
 		stm32_serial_enable_wakeup(port, false);
 
+	pinctrl_pm_select_sleep_state(dev);
+
 	return 0;
 }
 
 static int stm32_serial_resume(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
+
+	pinctrl_pm_select_default_state(dev);
 
 	if (device_may_wakeup(dev))
 		stm32_serial_enable_wakeup(port, false);