mvebu: gpio-mvebu IRQ index error kernel backport

Backport the upstream kernel fix 525b0858ff to get rid of the kernel
messages:

mvebu-gpio xxxxxx.gpio: IRQ index 3 not found

Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>

target/linux/mvebu/patches-5.4/007-gpio-mvebu-avoid_error_message_for_optional_IRQ.patch

@@ -0,0 +1,33 @@
+From 525b0858ff2fdb78defec2d4d6d63baaa423d5fd Mon Sep 17 00:00:00 2001
+From: Chris Packham <chris.packham@alliedtelesis.co.nz>
+Date: Fri, 13 Mar 2020 16:42:44 +1300
+Subject: [PATCH] gpio: mvebu: avoid error message for optional IRQ
+
+platform_get_irq() will generate an error message if the requested irq
+is not present
+
+  mvebu-gpio f1010140.gpio: IRQ index 3 not found
+
+use platform_get_irq_optional() to avoid the error message being
+generated.
+
+Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
+Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
+Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
+---
+ drivers/gpio/gpio-mvebu.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
+index d2b999c7987f1..3c9f4fb3d5a28 100644
+--- a/drivers/gpio/gpio-mvebu.c
++++ b/drivers/gpio/gpio-mvebu.c
+@@ -1245,7 +1245,7 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
+ 	 * pins.
+ 	 */
+ 	for (i = 0; i < 4; i++) {
+-		int irq = platform_get_irq(pdev, i);
++		int irq = platform_get_irq_optional(pdev, i);
+ 
+ 		if (irq < 0)
+ 			continue;