ARM: dt: tegra20: Rename "emc" to "memory-controller"

Use a more plain english name.
Signed-off-by: NHiroshi DOYU <hdoyu@nvidia.com>
[swarren: also rename the node in tegra-seaboard.dts]
Signed-off-by: NStephen Warren <swarren@nvidia.com>

arch/arm/boot/dts/tegra-seaboard.dts

@@ -334,7 +334,7 @@
 		};
 	};
 
-	emc {
+	memory-controller@0x7000f400 {
 		emc-table@190000 {
 			reg = <190000>;
 			compatible = "nvidia,tegra20-emc-table";

arch/arm/boot/dts/tegra20.dtsi

@@ -177,7 +177,7 @@
 		       0x58000000 0x02000000>;	/* GART aperture */
 	};
 
-	emc {
+	memory-controller@0x7000f400 {
 		compatible = "nvidia,tegra20-emc";
 		reg = <0x7000f400 0x200>;
 		#address-cells = <1>;