Revert "arm64: tegra: Disable ISO SMMU for Tegra194"

This reverts commit ebea268ea5.

Mmu is now being enabled for the display controllers.

Signed-off-by: Aaron Kling <webgeek1234@gmail.com>

arch/arm64/boot/dts/nvidia/tegra194.dtsi

@@ -1819,7 +1819,7 @@
 			#iommu-cells = <1>;
 
 			nvidia,memory-controller = <&mc>;
-			status = "disabled";
+			status = "okay";
 		};
 
 		smmu: iommu@12000000 {