regulator: dt-bindings: adi,adp5055-regulator: Add adp5055 support

Add documentation for devicetree bindings for ADP5055. The device consists
of 3 buck regulators able to connect to high input voltages of up to 18V
with no preregulators.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
Link: https://patch.msgid.link/20250409-upstream-adp5055-v6-1-faa6e810deb1@analog.com


Signed-off-by: Mark Brown <broonie@kernel.org>