ARM: tegra: Add EMC to Tegra124 device tree

This adds a node for the EMC memory controller. It is always enabled, but only
provides read-only functionality without board-specific timing tables.
Signed-off-by: NMikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra124.dtsi

@@ -207,6 +207,7 @@
 		reg = <0x0 0x60006000 0x0 0x1000>;
 		#clock-cells = <1>;
 		#reset-cells = <1>;
+		nvidia,external-memory-controller = <&emc>;
 	};
 
 	flow-controller@0,60007000 {
@@ -580,6 +581,13 @@
 		#iommu-cells = <1>;
 	};
 
+	emc: emc@0,7001b000 {
+		compatible = "nvidia,tegra124-emc";
+		reg = <0x0 0x7001b000 0x0 0x1000>;
+
+		nvidia,memory-controller = <&mc>;
+	};
+
 	sata@0,70020000 {
 		compatible = "nvidia,tegra124-ahci";