OpenWrt support for Xiaomi AX3000T

[remittor]

@KhetagAb

<5>[    1.201840] Creating 9 MTD partitions on "spi0.0":
<5>[    1.206911] 0x000000000000-0x000000100000 : "BL2"

Try this:

opkg install kmod-mtd-rw
insmod mtd-rw i_want_a_brick=1
mtd write preloader.bin BL2