Kconfig-related options not shown in ./configure --help

tag: v4.1.0-rc0

I notice these options not documented by '--help':

  --with-default-devices) default_devices="yes"
  --without-default-devices) default_devices="no"

We might have other options not documented too.

Fixed here:
https://gitlab.com/qemu-project/qemu/-/commit/c035c8d6f54