serial: omap: make sure to suspend device before remove

before removing the driver, let's make sure
to force device into a suspended state in order
to conserve power.
Tested-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/omap-serial.c

@@ -1369,6 +1369,7 @@ static int serial_omap_remove(struct platform_device *dev)
 {
 	struct uart_omap_port *up = platform_get_drvdata(dev);
 
+	pm_runtime_put_sync(up->dev);
 	pm_runtime_disable(up->dev);
 	uart_remove_one_port(&serial_omap_reg, &up->port);
 	pm_qos_remove_request(&up->pm_qos_request);