linux: cpupower needs gettext

linux: cpupower needs gettext

The cpupower linux tool needs gettext, always (even without locales).

We need to disable NLS, otherwise it tries to compile the .po files.
We also need to pass -lintl, otherwise it forgets to link with it
(because, the world is glibc-only, you did not know? And glibc does not
need we link with -lintl, so why would we? Oh, yes, we also reinvented
our super intelligent one-off Makefile rather than use one of the
standard buildsystems).

Fixes #9181:

      CC       utils/helpers/sysfs.o
    In file included from utils/helpers/amd.c:9:0: ./utils/helpers/helpers.h:13:21: fatal error: libintl.h: No such file or directory
     #include <libintl.h>
                         ^

Without NLS=false (yes, we could depend on host-gettext):

      MSGFMT   po/de.gmo
    make[3]: msgfmt: Command not found

Without LDFLAGS=-lintl:

      CC       cpupower
    ./utils/cpupower.o: In function `main':
    cpupower.c:(.text.startup+0x1a4): undefined reference to `libintl_textdomain'
    ./utils/idle_monitor/cpupower-monitor.o: In function `list_monitors':
    cpupower-monitor.c:(.text+0x5dc): undefined reference to `libintl_gettext'
    ./utils/cpupower-set.o: In function `cmd_set':
    cpupower-set.c:(.text+0x38): undefined reference to `libintl_textdomain'
    ./utils/cpupower-info.o: In function `cmd_info':
    cpupower-info.c:(.text+0x20): undefined reference to `libintl_textdomain'
    collect2: error: ld returned 1 exit status

Reported-by: Joergen Pihlflyckt <Jorgen.Pihlflyckt@ajeco.fi>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Joergen Pihlflyckt <Jorgen.Pihlflyckt@ajeco.fi>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>