MAINTAINERS: Add scripts/install.sh into Kbuild entry

MAINTAINERS: Add scripts/install.sh into Kbuild entry

The common installation code is in scripts/install.sh, add it into
Kbuild entry to reflect the reality.

With this updated entry, folks running get_maintainer.pl on patches
that touch scripts/install.sh will know to send it to linux-kbuild@
as well.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://patch.msgid.link/20260120123730.30487-2-yangtiezhu@loongson.cn
[nathan: Alphabetize entry]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>