linux-phytec-ti

gpio: pca953x: Add support for the TI TCA9539

The TI TCA9539 is a variant of the PCA953x GPIO expander,
with 16 GPIOs and interrupt functionality.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>