alsa-utils: fix linking with intl

alsa-utils needs to link with intl if the toolchain needs gettext and
locale is set. Otherwise we will see an error like this one:

alsamixer-cli.o: In function `main':
cli.c:(.text.startup+0x4d): undefined reference to `libintl_textdomain'
cli.c:(.text.startup+0xc1): undefined reference to `libintl_gettext'
cli.c:(.text.startup+0xd5): undefined reference to `libintl_gettext'
cli.c:(.text.startup+0xe9): undefined reference to `libintl_gettext'
cli.c:(.text.startup+0x1fd): undefined reference to `libintl_gettext'
cli.c:(.text.startup+0x223): undefined reference to `libintl_gettext'

Fixes:
  http://autobuild.buildroot.net/results/707/707016a2490fc97b98d17e2b6a9c6423a56bb4a9/



[Peter: correct autobuilder reference]
Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>