dt-bindings: regulator: Add Fitipower FP9931/JD9930

dt-bindings: regulator: Add Fitipower FP9931/JD9930

Document the FP9931/JD9930. As the FP9931 is a clear subset of the JD9930,
define it as a fallback compatible. GPIO names are same as in the datasheet
except for the EN pad which is described as "enable".

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://patch.msgid.link/20251115-fp9931-submit-v3-2-92f5d0772b68@kemnade.info
Signed-off-by: Mark Brown <broonie@kernel.org>