kconfig: make use of menu_get_ext_help in gconfig

Futhermore, gconfig interface lack the "search a symbol" function, do later.

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
[sam: fix SEGV in gconfig]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2 files changed