anv: move to using shared wsi code

This moves the shared code to a common subdirectory
and makes anv linked to that code instead of the copy
it was using.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
diff --git a/src/Makefile.am b/src/Makefile.am
index b63d135..1347120 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -115,6 +115,10 @@
 SUBDIRS += intel/tools
 endif
 
+if HAVE_VULKAN_COMMON
+SUBDIRS += vulkan/wsi
+endif
+
 ## Requires the i965 compiler (part of mesa) and wayland-drm
 if HAVE_INTEL_VULKAN
 SUBDIRS += intel/vulkan