dt-bindings: regulator: qcom-labibb-regulator: document the pmi8950 labibb regulator

Document the pmi8950 labibb regulator with the pmi8998 compatible
as fallback since they share the same hardware settings.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20241115-topic-sdm450-upstream-lab-ibb-bindings-v1-1-1f4bff4583b0@linaro.org


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