pinctrl/nomadik: use zero as default irq_start

The irqdomain semantics were supposed to be such that a linear
domain would be used if the passed first_irq was zero or
negative, but I got it wrong so only passing zero as first_irq
will work properly. Well, zero is NO_IRQ these days so let's
pass zero. The semantics of irqdomain_add_simple() will be
fixed in a separate patch.
Acked-by: Lee Jones <lee.jones@linaro.org>
Reported-by: Rikard Olsson <rikard.p.olsson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-nomadik.c

@@ -1281,7 +1281,7 @@ static int __devinit nmk_gpio_probe(struct platform_device *dev)
 	struct clk *clk;
 	int secondary_irq;
 	void __iomem *base;
-	int irq_start = -1;
+	int irq_start = 0;
 	int irq;
 	int ret;