libxml2: security bump to version 2.9.2

Fixes:
CVE-2014-3660 - billion laugh variant
CVE-2014-0191 - Do not fetch external parameter entities

Also add hash file.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libxml2/libxml2.hash

@@ -0,0 +1,2 @@
+# Locally calculated after checking pgp signature
+sha256	5178c30b151d044aefb1b08bf54c3003a0ac55c59c866763997529d60770d5bc	libxml2-2.9.2.tar.gz

package/libxml2/libxml2.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBXML2_VERSION = 2.9.1
+LIBXML2_VERSION = 2.9.2
 LIBXML2_SITE = ftp://xmlsoft.org/libxml2
 LIBXML2_INSTALL_STAGING = YES
 LIBXML2_AUTORECONF = YES
@@ -19,6 +19,7 @@ endif
 LIBXML2_CONF_OPTS = --with-gnu-ld --without-python --without-debug --without-lzma
 
 HOST_LIBXML2_DEPENDENCIES = host-pkgconf
+LIBXML2_DEPENDENCIES = host-pkgconf
 
 HOST_LIBXML2_CONF_OPTS = --without-zlib --without-lzma --without-python