libarchive: bump to version 2.8.4

The libxml2 dependency is new in this version, and does not behave nicely with
cross compile. The configure script looks for the host xml2-config. Add
'--disable-xml2' as a workaround for now.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/libarchive/libarchive.mk

@@ -3,7 +3,7 @@
 # libarchive (reusable C library for archive formats)
 #
 #############################################################
-LIBARCHIVE_VERSION = 2.7.1
+LIBARCHIVE_VERSION = 2.8.4
 LIBARCHIVE_SITE = http://libarchive.googlecode.com/files/
 LIBARCHIVE_SOURCE = libarchive-$(LIBARCHIVE_VERSION).tar.gz
 LIBARCHIVE_INSTALL_STAGING = YES
@@ -14,6 +14,7 @@ LIBARCHIVE_DEPENDENCIES = zlib
 endif
 
 LIBARCHIVE_CONF_OPT = \
+	--without-xml2 \
 	$(if $(BR2_PACKAGE_LIBARCHIVE_BSDTAR),--enable-bsdtar,--disable-bsdtar) \
 	$(if $(BR2_PACKAGE_LIBARCHIVE_BSDCPIO),--enable-bsdcpio,--disable-bsdcpio)