Drivers: gpio: Fix spelling errors

Fixed several spelling errors in gpio-lynxpoint, gpio-pca953x,
gpio-tegra, gpio-zynq, gpiolib-of, gpiolib.

Signed-off-by: Colin Cronin <colinpatrickcronin@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>