gpio: pca953x: Add support for the PCAL9535

The PCAL9535 is compatible to the PCA9535. Additionally, it comes with
interrupt support and input latching. Other features are not supported
by the GPIO subsystem.

Datasheet: https://www.nxp.com/docs/en/data-sheet/PCAL9535A.pdf


Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>