gpio-timberdale: fix a potential wrapping issue

commit d79550a7 upstream.

->last_ier is an unsigned long but the high bits can't be used int the
original code because the shift wraps.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpio/gpio-timberdale.c

@@ -116,7 +116,7 @@ static void timbgpio_irq_disable(struct irq_data *d)
 	unsigned long flags;
 
 	spin_lock_irqsave(&tgpio->lock, flags);
-	tgpio->last_ier &= ~(1 << offset);
+	tgpio->last_ier &= ~(1UL << offset);
 	iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 	spin_unlock_irqrestore(&tgpio->lock, flags);
 }
@@ -128,7 +128,7 @@ static void timbgpio_irq_enable(struct irq_data *d)
 	unsigned long flags;
 
 	spin_lock_irqsave(&tgpio->lock, flags);
-	tgpio->last_ier |= 1 << offset;
+	tgpio->last_ier |= 1UL << offset;
 	iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 	spin_unlock_irqrestore(&tgpio->lock, flags);
 }