libarchive: add conditional dependency on zlib

If zlib is selected, then it should be built before libarchive so that
libarchive picks up the headers and includes support for zlib
compression.

Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/libarchive/libarchive.mk

@@ -10,6 +10,10 @@ LIBARCHIVE_LIBTOOL_PATCH = NO
 LIBARCHIVE_INSTALL_STAGING = YES
 LIBARCHIVE_INSTALL_TARGET = YES
 
+ifeq ($(BR2_PACKAGE_ZLIB),y)
+LIBARCHIVE_DEPENDENCIES = zlib
+endif
+
 LIBARCHIVE_CONF_OPT = \
 	$(if $(BR2_PACKAGE_LIBARCHIVE_BSDTAR),--enable-bsdtar,--disable-bsdtar) \
 	$(if $(BR2_PACKAGE_LIBARCHIVE_BSDCPIO),--enable-bsdcpio,--disable-bsdcpio)