serial: imx: Grab port lock in imx_uart_enable_wakeup()

The port lock needs to be held when doing read-modify-write on UCR1 and
UCR3.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Link: https://lore.kernel.org/r/20240913-serial-imx-lockfix-v1-1-4d102746c89d@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/imx.c

@@ -2580,10 +2580,13 @@ static void imx_uart_save_context(struct imx_port *sport)
 	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
+/* called with irq off */
 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
 {
 	u32 ucr3;
 
+	uart_port_lock(&sport->port);
+
 	ucr3 = imx_uart_readl(sport, UCR3);
 	if (on) {
 		imx_uart_writel(sport, USR1_AWAKE, USR1);
@@ -2603,6 +2606,8 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
 		}
 		imx_uart_writel(sport, ucr1, UCR1);
 	}
+
+	uart_port_unlock(&sport->port);
 }
 
 static int imx_uart_suspend_noirq(struct device *dev)