vulkan: automake: do not use EXTRA_DIST in a conditional

Otherwise the file might not end up in the tarball.

Fixes: dbd677efb42 "vulkan: add API registry"
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/src/Makefile.am b/src/Makefile.am
index f1fe515..12e5dcd 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -118,8 +118,8 @@
 
 if HAVE_VULKAN_COMMON
 SUBDIRS += vulkan/wsi
-EXTRA_DIST += vulkan/registry/vk.xml
 endif
+EXTRA_DIST += vulkan/registry/vk.xml
 
 ## Requires the i965 compiler (part of mesa) and wayland-drm
 if HAVE_INTEL_VULKAN