gpio: rcar: Fix typo in comment

"Positive" is spelled incorrectly as "Postive" in
comment fix this.

Signed-off-by: Ashish Chavan <ashish.gschavan@gmail.com>
Link: https://lore.kernel.org/r/20200209095600.16394-1-ashish.gschavan@gmail.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>