goldfish-opengl: nuke VirtioGpuStream

The VirtioGpuStream was used for the original bring-up of the
pipe_virglrenderer.  All users have now transitioned to the
VirtioGpuPipeStream and virtio ASG.

BUG=239639751
TEST=compile

Change-Id: Ifae199b3d04bae09ef094f1aa4823e1ac4c49890
8 files changed