complibs/cloog: create missing m4 dir

Because we now patch configure.in and configure, the Makefile quicks
in a re-build rule as the source files are now more recent than the
bundled generated files, and that fails because the m4 directory
is missing, although on some systems where aclocal is not installed,
the re-build rule does nothing (except a warning).

Always create tht directory.

Reported-by: Per Arnold Blaasmo <per-arnold.blaasmo@atmel.com>
[Also thanks to Thomas De Schampheleire <patrickdepinguin@gmail.com>
for some digging works on this issue]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

syntax: glob

# Generated files

configure

autom4te.cache

config.log

config.status

Makefile

*ct-ng*

docs/*ct-ng*.1

docs/*ct-ng*.1.gz

paths.mk

paths.sh

scripts/crosstool-NG.sh

scripts/saveSample.sh

scripts/showTuple.sh

kconfig/conf

kconfig/?conf

kconfig/**.o

kconfig/**.dep

kconfig/lex.backup

kconfig/lex.zconf.c

kconfig/zconf.hash.c

kconfig/zconf.tab.c

config/configure.in

config.gen/

.config

.config.2

# Temporaries

.*.swp

build.log

.config.old

# This is the place where toolchains are built

.build/

# .. and the legacy location

targets/