dt-bindings: pinctrl: xway: drop the deprecated compatible strings

This code are marked as deprecated since kernel 4.5[1]. Downstream OpenWRT
and upstream switched to the new string compatible 7 years ago. The old
compatible strings can safely be dropped.

[1] commit be14811c ("pinctrl/lantiq: introduce new dedicated devicetree bindings")

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230330212225.10214-2-olek2@wp.pl


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