utils/checkpackagelib: CommentsMenusPackagesOrder: only apply to top-level

utils/checkpackagelib: CommentsMenusPackagesOrder: only apply to top-level

The CommentsMenusPackagesOrder test is broken in various ways for files
other than package/Config.in and package/Config.in.host. Therefore, the
script gives bogus errors for various other Config.in files.

However, we don't really want to check those other files. Indeed, many
of them have a non-alphabetical ordering for good reasons.

Therefore, skip the check for files other than package/Config.in and
package/Config.in.host.

Fixes: https://gitlab.com/buildroot.org/buildroot/-/jobs/251214899
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Cc: Jerzy Grzegorek <jerzy.m.grzegorek@gmail.com>
Cc: Yann E. MORIN <yann.morin.1998@free.fr>
Acked-by: Yann E. MORIN <yann.morin.1998@free.fr>