kconfig/mconf: Initialize the default locale at startup

kconfig/mconf: Initialize the default locale at startup

[ Upstream commit 3927c4a1084c48ef97f11281a0a43ecb2cb4d6f1 ]

Fix bug where make menuconfig doesn't initialize the default locale, which
causes ncurses menu borders to be displayed incorrectly (lqqqqk) in
UTF-8 terminals that don't support VT100 ACS by default, such as PuTTY.

Signed-off-by: Jakub Horký <jakub.git@horky.net>
Link: https://patch.msgid.link/20251014154933.3990990-1-jakub.git@horky.net
[nathan: Alphabetize locale.h include]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>