arm64: tegra: Set reg property for display-hub on Tegra194

Technically the display-hub driver could access registers via the
specified region, though it practice it will do so via the display
controllers' register regions.
Signed-off-by: Thierry Reding <treding@nvidia.com>

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

@@ -493,6 +493,7 @@ host1x@13e00000 {
 
 			display-hub@15200000 {
 				compatible = "nvidia,tegra194-display", "simple-bus";
+				reg = <0x15200000 0x00040000>;
 				resets = <&bpmp TEGRA194_RESET_NVDISPLAY0_MISC>,
 					 <&bpmp TEGRA194_RESET_NVDISPLAY0_WGRP0>,
 					 <&bpmp TEGRA194_RESET_NVDISPLAY0_WGRP1>,