greybus: gpio: handle set_irq_flags api change

The ARM-specific set_irq_flags helper has been removed in 4.3. Instead
of doing conditional compilation on the kernel version to avoid build
breakages, simply use the genirq interface directly.
Suggested-by: Rob Herring <rob.herring@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/gpio.c

@@ -506,11 +506,7 @@ static int gb_gpio_irq_map(struct irq_domain *domain, unsigned int irq,
 
 	irq_set_chip_data(irq, ggc);
 	irq_set_chip_and_handler(irq, ggc->irqchip, ggc->irq_handler);
-#ifdef CONFIG_ARM
-	set_irq_flags(irq, IRQF_VALID);
-#else
 	irq_set_noprobe(irq);
-#endif
 	/*
 	 * No set-up of the hardware will happen if IRQ_TYPE_NONE
 	 * is passed as default type.
@@ -523,9 +519,6 @@ static int gb_gpio_irq_map(struct irq_domain *domain, unsigned int irq,
 
 static void gb_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
 {
-#ifdef CONFIG_ARM
-	set_irq_flags(irq, 0);
-#endif
 	irq_set_chip_and_handler(irq, NULL, NULL);
 	irq_set_chip_data(irq, NULL);
 }