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 <andrew@lunn.ch>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Fixes: 9dbd90f1 ("irqchip: Add support for Marvell Orion SoCs")
Cc: <stable@vger.kernel.org> # v3.11+
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

drivers/irqchip/irq-orion.c

@@ -111,7 +111,8 @@ IRQCHIP_DECLARE(orion_intc, "marvell,orion-intc", orion_irq_init);
 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;