gpio: lynxpoint: Use for_each_set_bit() in IRQ handler

	struct gpio_chip *gc = irq_desc_get_handler_data(desc);

	struct lp_gpio *lg = gpiochip_get_data(gc);

	struct irq_chip *chip = irq_data_get_irq_chip(data);

	u32 base, pin, mask;

	unsigned long reg, ena, pending;

	u32 base, pin;

	/* check from GPIO controller which pin triggered the interrupt */

	for (base = 0; base < lg->chip.ngpio; base += 32) {

		reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);

		ena = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE);

		while ((pending = (inl(reg) & inl(ena)))) {

		/* Only interrupts that are enabled */

		pending = inl(reg) & inl(ena);

		for_each_set_bit(pin, &pending, 32) {

			unsigned irq;

			pin = __ffs(pending);

			mask = BIT(pin);

			/* Clear before handling so we don't lose an edge */

			outl(mask, reg);

			outl(BIT(pin), reg);

			irq = irq_find_mapping(lg->chip.irq.domain, base + pin);

			generic_handle_irq(irq);

		}