kconfig: enhancing accessibility of lxdialog

Some fix that I forgot for good accessibility of lxdialog (the cursor
should always be left at the focus location):

Have the checklist display the currently highlighted entry last, for having
the cursor left on it (rather than on the last line of the list).

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>