dm: gpio: pca953x: Support PCA953X with 40 GPIOs

A DM driver for PCA953x was recently introduced by Peng Fan, which lacked
support for the 40 GPIO versions.

This patch adds support for these chips.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Peng Fan <van.freenix@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>