zabbix: add which to hostmakedepends; fixes cross

Patch libxml2.m4 to use which to find the pkg-config binary on the path.

srcpkgs/zabbix/patches/fix-libxml2_m4.patch

@@ -5,7 +5,7 @@
          PKG_PROG_PKG_CONFIG()
  
 -        if test -x "$PKG_CONFIG"; then
-+        if test -x "/usr/bin/$PKG_CONFIG"; then
++        if test -x $(which "$PKG_CONFIG"); then
  
              LIBXML2_CFLAGS="`$PKG_CONFIG --cflags libxml-2.0`"
  

srcpkgs/zabbix/template

@@ -1,12 +1,12 @@
 # Template file for 'zabbix'
 pkgname=zabbix
 version=4.4.10
-revision=1
+revision=2
 build_style=gnu-configure
 configure_args="--with-gnutls --with-libcurl --with-libxml2=yes --with-net-snmp
  --with-mysql --enable-server --enable-ipv6 --with-ssh2 --enable-agent
  --enable-proxy"
-hostmakedepends="automake libtool pkg-config"
+hostmakedepends="automake libtool pkg-config which"
 makedepends="gnutls-devel libcurl-devel libxml2-devel libevent-devel
  libmysqlclient-devel net-snmp-devel pcre-devel"
 depends="fping mysql"
@@ -21,7 +21,6 @@ conf_files="/etc/zabbix_server.conf"
 system_accounts="_zabbix_server"
 system_groups="_zabbix_server"
 make_dirs="/var/log/zabbix-server 0750 _zabbix_server _zabbix_server"
-nocross="Temporary: fails to find pkg-config"
 
 if [ "$CROSS_BUILD" ]; then
 	# configure scripts is bad at checking, problably runs code instead of