arm64: dts: msm8916: Add missing #phy-cells

Add a missing #phy-cells to the dsi-phy, to silence dtc warning.

Cc: Archit Taneja <architt@codeaurora.org>
Fixes: 305410ff ("arm64: dts: msm8916: Add display support")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

arch/arm64/boot/dts/qcom/msm8916.dtsi

@@ -906,6 +906,7 @@ dsi_phy0: dsi-phy@1a98300 {
 					    "dsi_phy_regulator";
 
 				#clock-cells = <1>;
+				#phy-cells = <0>;
 
 				clocks = <&gcc GCC_MDSS_AHB_CLK>;
 				clock-names = "iface_clk";