arm64: tegra: Rename EMC on Tegra132

Rename the EMC node to external-memory-controller according to device
tree best practices.
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm64/boot/dts/nvidia/tegra132.dtsi

@@ -604,7 +604,7 @@ mc: memory-controller@70019000 {
 		#iommu-cells = <1>;
 	};
 
-	emc: emc@7001b000 {
+	emc: external-memory-controller@7001b000 {
 		compatible = "nvidia,tegra132-emc", "nvidia,tegra124-emc";
 		reg = <0x0 0x7001b000 0x0 0x1000>;
 		clocks = <&tegra_car TEGRA124_CLK_EMC>;