ramips: mt7621: fix nand@0 reg node property invalid length

ramips: mt7621: fix nand@0 reg node property invalid length

Fixes following DTC warnings:

 Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 Warning (avoid_default_addr_size): /nand@1e003000/nand@0: Relying on default #address-cells value
 Warning (avoid_default_addr_size): /nand@1e003000/nand@0: Relying on default #size-cells value

In following DTSes:

 image-mt7621_asus_rt-ac65p.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_asus_rt-ac85p.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_hiwifi_hc5962.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_mediatek_mt7621-eval-board.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_netgear_r6220.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_netgear_r6260.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_netgear_r6350.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_netgear_r6850.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_netis_wf-2881.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_ubiquiti_edgerouterx.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_ubiquiti_edgerouterx-sfp.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_xiaomi_mir3g.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
 image-mt7621_xiaomi_mir3p.dtb: Warning (reg_format): /nand@1e003000/nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)

Fixes: b99c93689d2d ("ramips: mt7621: update dts and old NAND driver to use sub node")
Signed-off-by: Petr Štetiar <ynezz@true.cz>