ARM builds now work

[cbrake]

Only tested user-mode QEMU on x86, not on ARM host yet.

This is all transparent as Docker supports QEMU user mode.

yoe login: root
login[54]: root login on 'ttyAMA0'
~ #
~ #
~ # uname -a
Linux yoe 6.6.87 #1 SMP PREEMPT Tue Mar 31 16:16:21 UTC 2026 aarch64 GNU/Linux
~ # uname -m
aarch64
~ #