regulator: qcom_smd: Add s1 sub-node to mp5496 regulator

Adding s1 sub-node entry to mp5496 regulator node.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Devi Priya <quic_devipriy@quicinc.com>
Link: https://lore.kernel.org/r/20230407155727.20615-2-quic_devipriy@quicinc.com


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