package/dhcp: untar internal bind

Untar internal bind so libtool patches will be applied on bind's
libtool. This will fix:
 - installation of some libraries such as libisccfg. Indeed, if libtool
   is not patched those libraries will be "relinked" and so not
   installed.
 - build failures with riscv and or1k:

  Invalid configuration `riscv64-buildroot-linux-musl': machine `riscv64-buildroot' not recognized

  Invalid configuration `or1k-buildroot-linux-uclibc': machine `or1k-buildroot' not recognized

Fixes:
 - http://autobuild.buildroot.org/results/d25b76e628ffe5293c6bc1fd467a6b8966cb1bc2
 - http://autobuild.buildroot.org/results/ba3258d8df00a7626784189125f0202fb161c40e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Tested-by: Jan Havran <havran.jan@email.cz>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/dhcp/dhcp.mk

@@ -14,6 +14,13 @@ DHCP_CPE_ID_VENDOR = isc
 # internal bind does not support parallel builds.
 DHCP_MAKE = $(MAKE1)
 
+# untar internal bind so libtool patches will be applied on bind's libtool
+define DHCP_UNTAR_INTERNAL_BIND
+	$(TAR) xf $(@D)/bind/bind.tar.gz -C $(@D)/bind/
+endef
+
+DHCP_POST_EXTRACT_HOOKS = DHCP_UNTAR_INTERNAL_BIND
+
 # use libtool-enabled configure.ac
 define DHCP_LIBTOOL_AUTORECONF
 	cp $(@D)/configure.ac+lt $(@D)/configure.ac