venus: vtest to avoid prime blit with common wsi

Venus with vtest hits an assertion about wsi mem must have base_bo upon WSI_MEMORY_SIGNAL_SUBMIT_INFO_MESA, which results from vtest staying on prime blit path unexpectedly. This MR fixes VK_EXT_pci_bus_info ext support to allow vtest to provide properly info to avoid prime blit.

vkcube: ../src/virtio/vulkan/vn_queue.c:165: vn_queue_submission_prepare: Assertion `submit->wsi_mem->base_bo' failed.

Test: vtest and inside VMs with crosvm/qemu

Related MRs:

• protocol: https://gitlab.freedesktop.org/olv/venus-protocol/-/merge_requests/56
• VKR: virgl/virglrenderer!1001 (merged)