arm: dts: qcom: sc7180: Set the compatible string for the GPU SMMU

Set the qcom,adreno-smmu compatible string for the GPU SMMU to enable
split pagetables and per-instance pagetables for drm/msm.
Signed-off-by: NRob Clark <robdclark@chromium.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20200905200454.240929-21-robdclark@gmail.comSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

arch/arm64/boot/dts/qcom/sc7180.dtsi

@@ -2062,7 +2062,7 @@
 		};
 
 		adreno_smmu: iommu@5040000 {
-			compatible = "qcom,sc7180-smmu-v2", "qcom,smmu-v2";
+			compatible = "qcom,sc7180-smmu-v2", "qcom,adreno-smmu", "qcom,smmu-v2";
 			reg = <0 0x05040000 0 0x10000>;
 			#iommu-cells = <1>;
 			#global-interrupts = <2>;