vulkan/wsi: fix select_memory_type when all MTs are local
The intention is to pick the system memory for the prime blit dst, but that is not possible when all memory types are advertised to be local.
This fixes venus over vtest (i.e., unix socket) because the driver provides no PCI bus info and wsi_device_matches_drm_fd returns false. A driver might also use can_present_on_device to force prime blit.
Fixes: 46987559 ("vulkan/wsi: Fix prime blits to use system memory for the destination")
/cc @kwg @jekstrand @llandwerlin @airlied