ding-libs: fix build with !locale

It needs libiconv if the toolchain doesn't have iconv support.

Fixes:
http://autobuild.buildroot.net/results/60f/60f85a2144b167f33ed674ff5979c1ef20bc0555/
http://autobuild.buildroot.net/results/76d/76d249f5a85da72cc53a3e66202c372dc33c9c38/
http://autobuild.buildroot.net/results/9f7/9f78043f549e09d020d69f45cd26c3e43a91d9dc/
http://autobuild.buildroot.net/results/8a5/8a586b781b6923444857ef58de659e5f0e8652ee/

And many more.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ding-libs/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_DING_LIBS
 	bool "ding-libs"
 	select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT
+	select BR2_PACKAGE_LIBICONV if !BR2_ENABLE_LOCALE
 	depends on BR2_USE_WCHAR || !BR2_NEEDS_GETTEXT
 	help
 	  The ding-libs packages contain a set of libraries used by

package/ding-libs/ding-libs.mk

@@ -7,7 +7,9 @@
 DING_LIBS_VERSION = 0_4_0
 DING_LIBS_SOURCE = ding_libs-$(DING_LIBS_VERSION).tar.xz
 DING_LIBS_SITE = https://git.fedorahosted.org/cgit/ding-libs.git/snapshot
-DING_LIBS_DEPENDENCIES = $(if $(BR2_PACKAGE_GETTEXT),gettext) host-pkgconf
+DING_LIBS_DEPENDENCIES = host-pkgconf \
+	$(if $(BR2_PACKAGE_GETTEXT),gettext) \
+	$(if $(BR2_PACKAGE_LIBICONV),libiconv)
 DING_LIBS_INSTALL_STAGING = YES
 DING_LIBS_LICENSE = LGPLv3+ (library),GPLv3+ (test programs)
 DING_LIBS_LICENSE_FILES = COPYING COPYING.LESSER