all: fix wildcard to work with make-4.x

In make-3.8x, the $(wildacrd) function would sort the entries,
while in make-4.x, it would just return the entries in any
unpredictable order [*]

Use the $(sort) function to get reproducible behaviour.

[*] Well, most probably the roder the entries appear when read
from readdir()

Reported-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Tested-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>

 # This file adds functions to build the C library for bare metal (IE. none)

 # Copyright 2008 Yann E. MORIN

 # Licensed under the GPL v2. See COPYING in the root of this package

 do_libc_get() {

     :

 }

 do_libc_extract() {

     :

 }

 do_libc_check_config() {

     :

 }

 do_libc_start_files() {

     :

 }

 do_libc() {

     :

 }