How i compile XIAOMI R3G with SPI flash 16M?

i have replaced original bad 32 pins flash eeprom by a 8 pins W25Q128FV

a this time no problem with Padavan but:

How i modify files for compile OpenWRT for XIAOMI R3G with SPI flash 16M ?

mt7621_xiaomi_mir3g.dts
others files ?

or can use R3G V2 firmware ?

i have flashed with Openwrt but for WR1200JS and run !!!