This very short series creates a new src/wsi folder, and moves wayland-drm into it. Basically wsi stuff is scattered about, and is needed by multiple components within mesa, wayland-drm, for example, is used by EGL, GBM, and vulkan wayland-wsi. I think there's more that could be moved into wsi, we could move EGL, GBM, and GLX, and vulkan/wsi, for example.