package/libv4l: fix build with argp-standalone and NLS

Fix the following build failure with argp-standalone and NLS raised
since commit 5430c8fedd0392e79e0c011825b056fea129980a:

configure:19923: /home/giuliobenetti/autobuild/run/instance-2/output-1/host/bin/i686-linux-gcc -o conftest -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os -g0  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  conftest.c -largp  -largp >&5
/home/giuliobenetti/autobuild/run/instance-2/output-1/host/opt/ext-toolchain/bin/../lib/gcc/i686-buildroot-linux-uclibc/9.3.0/../../../../i686-buildroot-linux-uclibc/bin/ld: /home/giuliobenetti/autobuild/run/instance-2/output-1/host/i686-buildroot-linux-uclibc/sysroot/usr/lib/libargp.a(argp-parse.o): in function `argp_version_parser':
/home/giuliobenetti/autobuild/run/instance-2/output-1/build/argp-standalone-1.4.1/argp-parse.c:181: undefined reference to `libintl_dgettext'

[...]

checking for library containing argp_parse... no
configure: error: unable to find the argp_parse() function

Fixes:
 - http://autobuild.buildroot.org/results/b7b2253ac902b441cc6ff12500b56bd15c413d71

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/libv4l/libv4l.mk

@@ -27,7 +27,8 @@ LIBV4L_DEPENDENCIES += alsa-lib
 endif
 
 ifeq ($(BR2_PACKAGE_ARGP_STANDALONE),y)
-LIBV4L_DEPENDENCIES += argp-standalone
+LIBV4L_DEPENDENCIES += argp-standalone $(TARGET_NLS_DEPENDENCIES)
+LIBV4L_CONF_ENV += LIBS=$(TARGET_NLS_LIBS)
 endif
 
 LIBV4L_DEPENDENCIES += $(if $(BR2_PACKAGE_LIBICONV),libiconv)