package/gptfdisk: fix popt static build

Fix the following static build failure with popt and iconv raised since
bump to version 1.0.9 in commit 69015ce94ac3ffe7f349ec37868eea0d0ffec90e
and
https://sourceforge.net/p/gptfdisk/code/ci/122b58ad82f1a144226d262c87241ee035ed1aff
(which added an unified Makefile):

/home/autobuild/autobuild/instance-0/output-1/host/bin/mips64el-buildroot-linux-uclibc-g++ crc32.o support.o guid.o gptpart.o mbrpart.o basicmbr.o mbr.o gpt.o bsd.o parttypes.o attributes.o diskio.o diskio-unix.o sgdisk.o gptcl.o -static -liconv -lpopt  -o sgdisk
/home/autobuild/autobuild/instance-0/output-1/host/lib/gcc/mips64el-buildroot-linux-uclibc/11.3.0/../../../../mips64el-buildroot-linux-uclibc/bin/ld: /home/autobuild/autobuild/instance-0/output-1/host/mips64el-buildroot-linux-uclibc/sysroot/usr/lib64/../lib64/libpopt.a(poptint.o): in function `strdup_locale_from_utf8':
poptint.c:(.text+0x113c): undefined reference to `libiconv_open'

As can be seen above, this build failure is raised because -liconv is
added before -lpopt so use pkgconfig and SGDISK_LDLIBS

The addition of -liconv in LDLIBS could probably be removed in a
follow-up patch for next branch

Fixes:
 - http://autobuild.buildroot.org/results/c9f2c9e737c2dd1cd4c1a08a5e8a48165179282d

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit a38682dd54dde976836c37dcc30ec24baa474690)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/gptfdisk/gptfdisk.mk

@@ -15,7 +15,8 @@ GPTFDISK_TARGETS_$(BR2_PACKAGE_GPTFDISK_CGDISK) += cgdisk
 
 GPTFDISK_DEPENDENCIES += util-linux
 ifeq ($(BR2_PACKAGE_GPTFDISK_SGDISK),y)
-GPTFDISK_DEPENDENCIES += popt
+GPTFDISK_DEPENDENCIES += host-pkgconf popt
+GPTFDISK_SGDISK_LDLIBS += `$(PKG_CONFIG_HOST_BINARY) --libs popt`
 endif
 ifeq ($(BR2_PACKAGE_GPTFDISK_CGDISK),y)
 GPTFDISK_DEPENDENCIES += ncurses
@@ -32,7 +33,8 @@ endif
 
 define GPTFDISK_BUILD_CMDS
 	$(TARGET_MAKE_ENV) $(MAKE) $(TARGET_CONFIGURE_OPTS) -C $(@D) \
-		LDLIBS='$(GPTFDISK_LDLIBS)' $(GPTFDISK_TARGETS_y)
+		LDLIBS='$(GPTFDISK_LDLIBS)' \
+		SGDISK_LDLIBS='$(GPTFDISK_SGDISK_LDLIBS)' $(GPTFDISK_TARGETS_y)
 endef
 
 define GPTFDISK_INSTALL_TARGET_CMDS