[PATCH] watchdog: stm32_iwdg: fix DT backward compatibility

The commit 3ab1663af6c1 ("watchdog: stm32_iwdg: Add pretimeout support")
introduces the support for the pre-timeout interrupt.

The support for this interrupt is optional but the driver mandates the
interrupts property in the device-tree, breaking the compatibility with
existing device-trees.

Use the platform_get_irq_optional() API to comply with existing
device-trees.

Fixes: 3ab1663af6c1 ("watchdog: stm32_iwdg: Add pretimeout support")
Signed-off-by: Clément Le Goffic <redacted>
---

Please consider merging this patch in the v6.13 cycle to avoid breaking
the compatibility of the existing device-tree.

drivers/watchdog/stm32_iwdg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
index d700e0d49bb95..8ad06b54c5adc 100644
--- a/drivers/watchdog/stm32_iwdg.c
+++ b/drivers/watchdog/stm32_iwdg.c

@@ -286,7 +286,7 @@ static int stm32_iwdg_irq_init(struct platform_device *pdev,
 	if (!wdt->data->has_early_wakeup)
 		return 0;

-	irq = platform_get_irq(pdev, 0);
+	irq = platform_get_irq_optional(pdev, 0);
 	if (irq <= 0)
 		return 0;

base-commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4
--
2.34.1