gpio/mvebu: convert to use irq_domain_add_simple()

The MVEBU driver probably just wants a few IRQs. Using the simple
domain has the upside of allocating IRQ descriptors if need be,
especially in a SPARSE_IRQ environment.

Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mvebu.c

@@ -645,8 +645,8 @@ static int __devinit mvebu_gpio_probe(struct platform_device *pdev)
 			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
 
 	/* Setup irq domain on top of the generic chip. */
-	mvchip->domain = irq_domain_add_legacy(np, mvchip->chip.ngpio,
-					       mvchip->irqbase, 0,
+	mvchip->domain = irq_domain_add_simple(np, mvchip->chip.ngpio,
+					       mvchip->irqbase,
 					       &irq_domain_simple_ops,
 					       mvchip);
 	if (!mvchip->domain) {