scripts/config: hook to automation build script

Use the new .config manipulation tool to toggle CONFIG_DEBUG in the
Xen automation build script.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

automation/scripts/build

@@ -27,7 +27,8 @@ else
     # Start off with arch's defconfig
     make -C xen defconfig
 
-    echo "CONFIG_DEBUG=${debug}" >> xen/.config
+    debug="${debug:-n}"
+    xen/scripts/config --file xen/.config -${debug} DEBUG
 
     if [[ -n "${EXTRA_XEN_CONFIG}" ]]; then
         echo "${EXTRA_XEN_CONFIG}" >> xen/.config