ndisc6: fix build when libintl is enabled

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/ndisc6/ndisc6.mk

@@ -10,6 +10,11 @@ NDISC6_SITE = http://www.remlab.net/files/ndisc6/
 NDISC6_CONF_ENV = CC="$(TARGET_CC) -std=gnu99"
 NDISC6_CONF_OPT = --localstatedir=/var --disable-rpath --disable-suid-install
 
+ifeq ($(BR2_PACKAGE_LIBINTL),y)
+NDISC6_DEPENDENCIES += libintl
+NDISC6_CONF_ENV += LDFLAGS="$(TARGET_LDFLAGS) -lintl"
+endif
+
 NDISC6_BIN_ += dnssort # perl script
 NDISC6_BIN_$(BR2_PACKAGE_NDISC6_NAME2ADDR) += name2addr addr2name
 NDISC6_BIN_$(BR2_PACKAGE_NDISC6_TCPSPRAY) += tcpspray tcpspray6