dt-bindings: power: qcom,rpmpd: Add SA8155P

Add a compatible for SA8155P platforms and relevant defines to the
include file.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230411-topic-hanaau-v2-1-fd3d70844b31@linaro.org