irqchip: orion: Fix getting generic chip pointer.

Enabling SPARSE_IRQ shows up a bug in the irq-orion bridge interrupt
handler. The bridge interrupt is implemented using a single generic
chip. Thus the parameter passed to irq_get_domain_generic_chip()
should always be zero.

Signed-off-by: Andrew Lunn <[e-mail]>
Acked-by: Sebastian Hesselbarth <[e-mail]>
Fixes: 9dbd90f17e4f ("irqchip: Add support for Marvell Orion SoCs")
Cc: <[e-mail]> # v3.11+
Signed-off-by: Jason Cooper <[e-mail]>

drivers/irqchip/irq-orion.c

···
 static void orion_bridge_irq_handler(unsigned int irq, struct irq_desc *desc)
 {
 	struct irq_domain *d = irq_get_handler_data(irq);
-	struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, irq);
+
+	struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, 0);
 	u32 stat = readl_relaxed(gc->reg_base + ORION_BRIDGE_IRQ_CAUSE) &
 		   gc->mask_cache;