ARM: dts: imx: change ocotp node name on MXS SoCs

Change OCOTP node name from ocotp to efuse to be compliant
with yaml schema, it requires the nodename to be one of
"eeprom|efuse|nvram".

Signed-off-by: Anson Huang <[e-mail]>
Reviewed-by: Fugang Duan <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

arch/arm/boot/dts/imx23.dtsi

···
 				status = "disabled";
 			};
 
-			ocotp@8002c000 {
+			efuse@8002c000 {
 				compatible = "fsl,imx23-ocotp", "fsl,ocotp";
 				#address-cells = <1>;
 				#size-cells = <1>;

arch/arm/boot/dts/imx28.dtsi

···
 				status = "disabled";
 			};
 
-			ocotp: ocotp@8002c000 {
+			ocotp: efuse@8002c000 {
 				compatible = "fsl,imx28-ocotp", "fsl,ocotp";
 				#address-cells = <1>;
 				#size-cells = <1>;