leds: pca953x: Include the right header

This LED chip provides a GPIO driver, so include
<linux/gpio/driver.h> rather than the legacy header
<linux/gpio.h>.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>