linux-imx

gpio-timberdale: fix a potential wrapping issue

->last_ier is an unsigned long but the high bits can't be used int the
original code because the shift wraps.

Cc: stable@kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>