ARM: dts: ux500: switch to enable-gpios

The recommended name for enable GPIOs property in regulator-gpio is
"enable-gpios".  This is also required by bindings:

  ste-hrefv60plus-stuib.dtb: regulator-gpio: Unevaluated properties are not allowed ('enable-gpio' was unexpected)

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230726070353.103989-3-krzysztof.kozlowski@linaro.org


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