mediatek: filogic: fix SPI node reg size dtc warnings

mediatek: filogic: fix SPI node reg size dtc warnings

Add missing #address-cells and #size-cells to fix the
following dtc warnings:

../dts/mt7981b-cmcc-rax3000m-nand.dtso:67.5-15: Warning (reg_format): /fragment@4/__overlay__/spi_nand@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
mt7988a-rfb-snfi-nand.dtso:20.5-15: Warning (reg_format): /fragment@0/__overlay__/flash@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
mt7988a-rfb-spim-nand.dtso:22.5-15: Warning (reg_format): /fragment@0/__overlay__/flash@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
mt7988a-rfb-spim-nor.dtso:31.5-15: Warning (reg_format): /fragment@0/__overlay__/flash@0:reg: property has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>