dt-bindings: clock: qcom: describe the GPUCC clock for SA8775P

Add the compatible for the Qualcomm Graphics Clock control module present
on sa8775p platforms. It matches the generic QCom GPUCC description. Add
device-specific DT bindings defines as well.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230411125910.401075-2-brgl@bgdev.pl