arm64: dts: imx8mp-debix-som-a-bmb: Fix EEPROM #size-cells

The mac-address is passed as a subnode of the eeprom and its 'reg'
property describe a range of addresses in the eeprom.

Therefore, #size-cells should be set to 1 instead of 0.

This fixes the following schema warnings:

imx8mp-debix-som-a-bmb-08.dtb: eeprom@52: #size-cells:0:0: 1 was expected
	from schema $id: http://devicetree.org/schemas/eeprom/at24.yaml#
imx8mp-debix-som-a-bmb-08.dtb: eeprom@52: mac-address@0:reg: [[0], [12]] is too long
	from schema $id: http://devicetree.org/schemas/eeprom/at24.yaml#
imx8mp-debix-som-a-bmb-08.dtb: eeprom@52: mac-address@c:reg: [[12], [12]] is too long
	from schema $id: http://devicetree.org/schemas/eeprom/at24.yaml#
imx8mp-debix-som-a-bmb-08.dtb: eeprom@52: Unevaluated properties are not allowed ('#address-cells', '#size-cells', 'mac-address@0', 'mac-address@c' were unexpected)
	from schema $id: http://devicetree.org/schemas/eeprom/at24.yaml#Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp-debix-som-a-bmb-08.dts

@@ -220,7 +220,7 @@ eeprom@52 {
 		reg = <0x52>;
 		pagesize = <16>;
 		#address-cells = <1>;
-		#size-cells = <0>;
+		#size-cells = <1>;
 
 		/* MACs stored in ASCII */
 		ethmac1: mac-address@0 {