gpio: xgene-sb: Make irq_chip immutable

Kernel warns about mutable irq_chips:
"not an immutable chip, please consider fixing!"

Constify xgene_gpio_sb_irq_chip, flag the irq_chip as IRQCHIP_IMMUTABLE,
add the new helper functions, and call the appropriate gpiolib functions.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250509-gpio-v1-7-639377c98288@nxp.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: MrVan

drivers/gpio/gpio-xgene-sb.c

@@ -103,12 +103,32 @@ static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
 		return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
 }
 
-static struct irq_chip xgene_gpio_sb_irq_chip = {
+static void xgene_gpio_sb_irq_mask(struct irq_data *d)
+{
+	struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
+
+	irq_chip_mask_parent(d);
+
+	gpiochip_disable_irq(&priv->gc, d->hwirq);
+}
+
+static void xgene_gpio_sb_irq_unmask(struct irq_data *d)
+{
+	struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
+
+	gpiochip_enable_irq(&priv->gc, d->hwirq);
+
+	irq_chip_unmask_parent(d);
+}
+
+static const struct irq_chip xgene_gpio_sb_irq_chip = {
 	.name           = "sbgpio",
 	.irq_eoi	= irq_chip_eoi_parent,
-	.irq_mask       = irq_chip_mask_parent,
-	.irq_unmask     = irq_chip_unmask_parent,
+	.irq_mask       = xgene_gpio_sb_irq_mask,
+	.irq_unmask     = xgene_gpio_sb_irq_unmask,
 	.irq_set_type   = xgene_gpio_sb_irq_set_type,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
 };
 
 static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)