arm64: dts: imx8mm-beacon-som: Fix atmel,24c64 EEPROM compatible

Correct the EEPROM node compatible to match device tree schema (invalid
space, unknown ID) to fix dtbs_check warnings:

  arch/arm64/boot/dts/freescale/imx8mm-beacon-kit.dt.yaml: eeprom@50:
    compatible: ['microchip, at24c64d', 'atmel,24c64'] is not valid under any of the given schemas
  arch/arm64/boot/dts/freescale/imx8mm-beacon-kit.dt.yaml: eeprom@50:
    compatible:0: 'microchip, at24c64d' does not match '^[a-zA-Z][a-zA-Z0-9,+\\-._]+$'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi

@@ -184,7 +184,7 @@ &i2c3 {
 	status = "okay";
 
 	eeprom@50 {
-		compatible = "microchip, at24c64d", "atmel,24c64";
+		compatible = "microchip,24c64", "atmel,24c64";
 		pagesize = <32>;
 		read-only;	/* Manufacturing EEPROM programmed at factory */
 		reg = <0x50>;