meson: set up a proper internal dependency for xmlconfig

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
10 jobs for !1174 with xmlconfig-fixes in 8 minutes (queued for 1 second)
detached
Status Job ID Name Coverage
  Containers Build
passed debian #385395

00:00:19

 
  Build+Test
passed meson-clang #385397

00:06:14

passed meson-clover #385401

00:07:39

passed meson-main #385400

00:04:28

passed meson-swr-glvnd #385396

00:05:11

passed meson-vulkan #385402

00:01:42

passed scons-llvm #385404

00:03:07

passed scons-nollvm #385403

00:04:26

passed scons-swr #385398

00:04:26

passed scons-win64 #385399

00:05:41