pinctrl/nomadik: use irq_create_mapping()

Since in the DT case, the linear domain path will not allocate
descriptors for the IRQs, we need to use irq_create_mapping()
for mapping hwirqs to Linux IRQs, so these descriptors get
created on-the-fly in this case.

ChangeLog v1->v2:

- Just use irq_create_mapping() in the .to_irq function since
  this is called before unmasking or enabling any interrupt
  lines, so irq_find_mapping() should be sufficient for the
  IRQ handler function.

Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-nomadik.c

@@ -1056,7 +1056,7 @@ static int nmk_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 	struct nmk_gpio_chip *nmk_chip =
 		container_of(chip, struct nmk_gpio_chip, chip);
 
-	return irq_find_mapping(nmk_chip->domain, offset);
+	return irq_create_mapping(nmk_chip->domain, offset);
 }
 
 #ifdef CONFIG_DEBUG_FS