Many other filesystems need it but vfat no longer does. It calls
built-in UTF-8 functions directly, while nominally using nls_ascii
as its I/O charset.
So many module packages depend on core-modules already that almost
every installer image includes it.
The only obvious exceptions are the sh4 installer builds, as there
was no core-modules package on sh4. For consistency, include the
default set of modules in its kernel-image package now.