tty: serial: fsl_lpuart: Add missing wakeup event reporting

Current lpuart wakeup event would not report itself as wakeup source
through sysfs. Add pm_wakeup_event() to support it.

Signed-off-by: Sherry Sun <[e-mail]>
Reviewed-by: Frank Li <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/fsl_lpuart.c

···
 static int lpuart_resume_noirq(struct device *dev)
 {
 	struct lpuart_port *sport = dev_get_drvdata(dev);
+	struct tty_port *port = &sport->port.state->port;
+	bool wake_active;
 	u32 stat;
 
 	pinctrl_pm_select_default_state(dev);
···
 		if (lpuart_is_32(sport)) {
 			stat = lpuart32_read(&sport->port, UARTSTAT);
 			lpuart32_write(&sport->port, stat, UARTSTAT);
+
+			/* check whether lpuart wakeup was triggered */
+			wake_active = stat & (UARTSTAT_RDRF | UARTSTAT_RXEDGIF);
+
+			if (wake_active && irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq)))
+				pm_wakeup_event(tty_port_tty_get(port)->dev, 0);
 		}
 	}