linux-phytec-fsl

gpio: pca953x: Add compatible strings to gpio-pca953x driver

Even though the device tree binding code was already written, the
compatible strings were not yet in the driver.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>