platform/generic-x86_64: Add empty vsock rust crate depending on virtio-drivers am: 12577961f3

Original change: https://android-review.googlesource.com/c/trusty/lk/trusty/+/2964343

Change-Id: Ifba6b89ad0b463023dbe9c7f7aba41cc3d07d5f1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>