regulator: dt-bindings: qcom,rpmh: Add compatible for PMC8180

regulator: dt-bindings: qcom,rpmh: Add compatible for PMC8180

Commit 71ca776a8885 ("regulator: qcom-rpmh: Add pmc8180 and pmc8180c")
introduced these compatible's but the yaml conversion commit
7255f98d08c7 ("regulator: Convert RPMh regulator bindings to YAML")
seems to have dropped it

So bring it back!

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230325122444.249507-9-vkoul@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>