arm64: dts: qcom: msm8996: mark apcs as clock provider

Now as we added the APCS clock controller support, mark apcs device as
clock provider by adding #clock-cells property.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111191634.2509616-1-dmitry.baryshkov@linaro.org

arch/arm64/boot/dts/qcom/msm8996.dtsi

@@ -3488,6 +3488,7 @@ apcs_glb: mailbox@9820000 {
 			reg = <0x09820000 0x1000>;
 
 			#mbox-cells = <1>;
+			#clock-cells = <0>;
 		};
 
 		timer@9840000 {