X5: copy content of FMU_Q.mix to FMU_X5.mix because FMU_Q was used previously by the X5 startup script

The x5 startup script was changed to use FMU_X5 instead of FMU_Q in 068cc190e20b8901b8e4128f3c21200724f0cd4f but the x5 was not tested with the old content of FMU_X5 to my knowledge.