pinctrl: bcm2835: Accept fewer than expected IRQs

The downstream .dts files only request two GPIO IRQs. Truncate the
array of parent IRQs when irq_of_parse_and_map returns 0.
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Ivan T. Ivanov <iivanov@suse.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210521090158.26932-1-iivanov@suse.deSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/bcm/pinctrl-bcm2835.c

@@ -1274,9 +1274,13 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
 		char *name;
 
 		girq->parents[i] = irq_of_parse_and_map(np, i);
-		if (!is_7211)
+		if (!is_7211) {
+			if (!girq->parents[i]) {
+				girq->num_parents = i;
+				break;
+			}
 			continue;
-
+		}
 		/* Skip over the all banks interrupts */
 		pc->wake_irq[i] = irq_of_parse_and_map(np, i +
 						       BCM2835_NUM_IRQS + 1);