dt-bindings: clock: qcom-rpmhcc: document the clock for sa8775p

Add a new compatible for SA8775P platforms.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109174511.1740856-5-brgl@bgdev.pl