pinctrl: cygnus: fixed typo in the gpio driver

Fixed a small typo in the Cygnus GPIO driver

Signed-off-by: Jason Uy <jasonuy@broadcom.com>
Signed-off-by: Ray Jui <rjui@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>