Removing the word in `ct-ng menuconfig` does not help. It is because the _real_ tuple is a four-part tuple,
so if you give an empty vendor-string, ct-ng will insert ‘unknown’ to ensure the tuple is complete.
To obtain `arm-linux-gnueabi-` toolcahin touple style, use “Tuple’s sed transform” or “Tuple’s alias” option in menuconfig.
The first is a sed expression that will transform the tuple, so you could enter something like: `s/-unknown//`, while the second is a hardcoded value (not recommend for use).