configure: disable stubdomain build by default on FreeBSD

Stubdomain code as-is doesn't compile on FreeBSD, so disable it for
now in order to have a working build.

Please re-run autoconf after committing.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

configure.ac

@@ -28,6 +28,13 @@ case "$host_cpu" in
         ;;
 esac
 
+dnl Stubdomains need some work in order to compile on FreeBSD
+case "$host_os" in
+    freebsd*)
+        arch_enable_stubdom=n
+        ;;
+esac
+
 AX_SUBSYSTEM_DEFAULT_ENABLE([xen])
 AX_SUBSYSTEM_DEFAULT_ENABLE([tools])
 AX_SUBSYSTEM_CONDITIONAL([stubdom], $arch_enable_stubdom)