Revert "FROMLIST: dma-buf: add support for virtio exported objects"

This reverts commit 0787bdf5.

No AOSP user and hasn't been exported since android11-5.4.

Cc: David Stevens <stevensd@chromium.org>
Suggested-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: I19eaa27d3c9cfdad1f8b47ff559632034c660b60