gpio: ucb1400: Use proper header

The UCB1400 implements a GPIO driver so it needs to include the
<linux/gpio/driver.h> header, not the legacy <linux/gpio.h> header.
Compile tested on pxa_defconfig.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>