vulkan: fix build dependency issue with generated files
On machines with many cores, you can run into that issue :
../mesa-9999/src/vulkan/overlay-layer/overlay.cpp:42:10: fatal error: vk_enum_to_str.h: No such file or directorySigned-off-by: Lionel Landwerlin lionel.g.landwerlin@intel.com Reported-by: Jan Ziak Cc: mesa-stable@lists.freedesktop.org
/cc @atomsymbol