hw/intc/exynos4210_combiner: Don't overrun output_irq array in init

The Exynos4210 combiner has IIC_NIRQ inputs and IIC_NGRP outputs;
use the correct constant in the loop initializing our output
sysbus IRQs so that we don't overrun the output_irq[] array.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1392659611-8439-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Andreas Färber <afaerber@suse.de>
Cc: qemu-stable@nongnu.org
