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

Use a more plain english name.

Signed-off-by: Hiroshi DOYU <[e-mail]>
[swarren: also rename the node in tegra-seaboard.dts]
Signed-off-by: Stephen Warren <[e-mail]>

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

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

arch/arm/boot/dts/tegra20.dtsi

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