Add missing `#address-cells = <1>;` and `#size-cells = <0>;` properties
to `ð` and `&wifi` nodes to resolve the following warnings.
```
../dts/mt7981b-elecom-wrc-x3000gs3.dts:114.3-13: Warning (reg_format): /soc/ethernet@
15100000/mac@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
../dts/mt7981b-elecom-wrc-x3000gs3.dts:129.3-13: Warning (reg_format): /soc/ethernet@
15100000/mac@1:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
../dts/mt7981b-elecom-wrc-x3000gs3.dts:372.3-13: Warning (reg_format): /soc/wifi@
18000000/band@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
../dts/mt7981b-elecom-wrc-x3000gs3.dts:378.3-13: Warning (reg_format): /soc/wifi@
18000000/band@1:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
../dts/mt7981b-elecom-wrc-x3000gs3.dts:112.15-125.4: Warning (avoid_default_addr_size): /soc/ethernet@
15100000/mac@0: Relying on default #address-cells value
../dts/mt7981b-elecom-wrc-x3000gs3.dts:112.15-125.4: Warning (avoid_default_addr_size): /soc/ethernet@
15100000/mac@0: Relying on default #size-cells value
../dts/mt7981b-elecom-wrc-x3000gs3.dts:127.15-136.4: Warning (avoid_default_addr_size): /soc/ethernet@
15100000/mac@1: Relying on default #address-cells value
../dts/mt7981b-elecom-wrc-x3000gs3.dts:127.15-136.4: Warning (avoid_default_addr_size): /soc/ethernet@
15100000/mac@1: Relying on default #size-cells value
../dts/mt7981b-elecom-wrc-x3000gs3.dts:371.9-375.4: Warning (avoid_default_addr_size): /soc/wifi@
18000000/band@0: Relying on default #address-cells value
../dts/mt7981b-elecom-wrc-x3000gs3.dts:371.9-375.4: Warning (avoid_default_addr_size): /soc/wifi@
18000000/band@0: Relying on default #size-cells value
../dts/mt7981b-elecom-wrc-x3000gs3.dts:377.9-381.4: Warning (avoid_default_addr_size): /soc/wifi@
18000000/band@1: Relying on default #address-cells value
../dts/mt7981b-elecom-wrc-x3000gs3.dts:377.9-381.4: Warning (avoid_default_addr_size): /soc/wifi@
18000000/band@1: Relying on default #size-cells value
```
Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/19530
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>