pinctrl: sx150x: Use maple tree register cache

The sx150x driver uses a rbtree register cache with no obvious reason for
specifically preferring it. The maple tree register cache is based on a
more modern data structure and makes implementation decisions more suitable
for modern systems so let's switch the driver to use that. No functional
change.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/20240924-pinctl-sx150x-maple-v1-1-17dcfefefd17@kernel.org


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>