dt-bindings: power: Add missing rpmpd rpmh regulator level

Add RPMH_REGULATOR_LEVEL_SVS_L0, used by sm8250.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Link: https://lore.kernel.org/r/20200709135251.643-13-jonathan@marek.ca


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>