gpio: Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc

Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc while we
already have a pointer to corresponding irq_desc.

Preparatory patch for the removal of the 'irq' argument from irq flow
handlers.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
index 7bd9f20..fa34438 100644
--- a/drivers/gpio/gpio-vf610.c
+++ b/drivers/gpio/gpio-vf610.c
@@ -120,7 +120,7 @@
 
 static void vf610_gpio_irq_handler(u32 irq, struct irq_desc *desc)
 {
-	struct vf610_gpio_port *port = irq_get_handler_data(irq);
+	struct vf610_gpio_port *port = irq_desc_get_handler_data(desc);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	int pin;
 	unsigned long irq_isfr;