Revert "gpio: merrifield: Restore use of irq_base"

This reverts commit 6658f87.

This revert is a prerequisite for the later revert of commit
8f86a5b.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-merrifield.c

@@ -455,7 +455,6 @@ static int mrfld_gpio_probe(struct pci_dev *pdev, const struct pci_device_id *id
 	if (!girq->parents)
 		return -ENOMEM;
 	girq->parents[0] = pdev->irq;
-	girq->first = irq_base;
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_bad_irq;